SpecialFunctions
http://www.openmath.org/CDs/SpecialFunctions
10/Nov/1999
private
This content dictionary contains the most commonly used special functions
in areas such as applied mathematics, chemistry, science, engineering,
physics and statistics.
Ying Xue and Stephen Watt, 2000.
ExpIntegralE
Exponential Integral
$E_n(z)$
The exponential integral function is defined by
$E_n(z)=\int_{1}^{\infty} \frac{e^{-zt}}{t^n}dt$ where
$(n=0, 1, 2, \dots;\ \Re{z}>0)$.
It has a branch cut along the negative real axis in the complex
$z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.1.2]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$E_n(\bar{z})=\overline{E_n(z)}$, symmetry
$E_{n+1}(z)=\frac{1}{n}[e^{-z}-zE_n(z)]$, $n=1, 2,
\dots$, recurrence relation
$\frac{dE_n(z)}{dz}=-E_{n-1}(z)$, $n=1, 2, \dots$,
derivative
$E_n(0)=\frac{1}{n-1}$, $n>1$, special value
$E_0(z)=\frac{e^z}{z}$, special value
ExpIntegralEi
Exponential Integral
$Ei(z)$
The exponential integral function is defined by
$Ei(z)=-\int_{-z}^{\infty} \frac{e^{-t}}{t}dt$, where the principal
value is taken. It has a branch cut along the negative real axis in
the complex $z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.1.2]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$Ei(z)=\gamma+ln(-z)+
\sum_{n=1}^{\infty} \frac{z^n}{n!n}$, series expansion
LogIntegral
Logarithmic Integral
$li(z)$
The logarithmic integral function is defined by
$li(z)=\int_{0}^{z} \frac{dt}{lnt}$, where the principal value is
taken. It has a branch cut along the negative real axis in the
complex $z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.1.3]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$li(z)=Ei(lnz)$
SinIntegral
Sine Integral
$Si(z)$
The sine integral is defined by $Si(z)=\int_{0}^{z} \frac{sint}{t}dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.2.1]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$Si(z)=\sum_{n=0}^{\infty} \frac{(-1)^{n}z^{2n+1}}{(2n+1)(2n+1)!}$,
series expansion
$Si(-z)=-Si(z)$, symmetry
$Si(\bar{z})=\overline{Si(z)}$, symmetry
CosIntegral
Cosine Integral
$Ci(z)$
The cosine integral is defined by
$Ci(z)=-\int_z^{\infty} \frac{cost}{t} dt$ where $|argz| \lt \pi$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.2.27]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$Ci(z)=\gamma + lnz + \sum_{n=1}^{\infty}
\frac{(-1)^{n}z^{2n}}{2n(2n)!}$, series expansion
symmetry relation: $Ci(\bar{z})=\overline{Ci(z)}$, symmetry
$Ci(-z)=Ci(z)-i \pi$, ($0 \lt argz \lt \frac{\pi}{2}$), symmetry
SinhIntegral
Hyperbolic Sine Integral Function
$Shi(z)$
The hyperbolic sine integral is defined by $Shi(z)=\int_{0}^{z}
\frac{sinht}{t} dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.2.3]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$Shi(z)=\sum_{n=0}^{\infty}\frac{z^{2n+1}}
{(2n+1)(2n+1)!}$, series expansion
CoshIntegral
Hyperbolic Cosine Integral Function
$Chi(z)$
The hyperbolic cosine integral is defined by $Chi(z)=\gamma
+ lnz + \int_{0}^{z} \frac{cosht-1}{t} dt$
where $\gamma=.5772156649 \dots$ is Euler's constant and $|argz|\lt \pi$.
It has a branch cut along the negative real axis in the complex $z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [5.2.4]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$Chi(z)=\gamma + lnz + \sum_{n=1}^{\infty} \frac{z^{2n}}{2n(2n)!}$,
series expansion
Gamma
Gamma Function
$\Gamma(z)$
The Euler Gamma function is defined by
$\Gamma(z)=\int_{0}^{\infty} t^{z-1}e^{-t} dt$. $Gamma(z)$
is a single valued and analytic over the entire complex plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [6.1.1]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$\Gamma(n)=1 \cdot 2 \cdot 3 \dots (n-1)n=n!$, integer
value
$\Gamma(z+1)=z \Gamma(z)=z!$, recurrence relation
$\Gamma(n+z)=(n-1+z)(n-2+z)\dots(1+z)\Gamma(1+z)$, recurrence
relation
$\Gamma(z) \Gamma(1-z)=-z \Gamma(-z) \Gamma(z)$,
reflection relation
$\Gamma(\frac{1}{2})=(-\frac{1}{2})!$, fractional value
$\Gamma(\frac{3}{2})=(\frac{1}{2})!$, fractional value
Digamma
Digamma Function
$\psi(z)$
The Digamma function is defined as
$\psi(z)=\frac{d[ln\Gamma(z)]}{dz}=\frac{\Gamma(z)^{\prime}}{\Gamma(z)}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [6.3.1]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$\psi(1)=-\gamma$, integer value
$\psi(n)=-\gamma+\sum_{k=1}^{n-1}k^{-1}$, $n \geq 2$,
integer value
$\psi(z+1)=\psi(z)+\frac{1}{z}$, recurrence relation
$\psi(1-z)=\psi(z)+\pi cot\pi z$, reflection relation
PolyGamma
Polygamma Function
$\psi^{(n)}(z)$
The Polygamma function is defined by
$\psi^{(n)}(z)
=\frac{d^n}{dz^n}\psi(z)=\frac{d^{n+1}}{dz^{n+1}}ln\Gamma(z)
=(-1)^{n+1}\int_{0}^{\infty}\frac{t^ne^{-zt}}{1-e^{-t}} dt$
where $n \ge 0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [6.4.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$\psi^{(n)}(1)=(-1)^{n+1}n! \zeta (n+1)$, $n>0$, integer
value
$\psi^{(n)}(\frac{1}{2})=(-1)^{n+1}n!(2^{n+1}-1)
\zeta(n+1)$, $n=1, 2, \dots$, fractional value
$\psi^{(n)}(z+1)=\psi^{(n)}(z)+(-1)^nn!z^{-n-1}$,
recurrence relation
$\psi^{(n)}(z)=(-1)^{n+1}n!\sum_{k=0}^{\infty}(z+k)^{-n-1}$
, $z \neq 0. -1. -2. \dots$, series expansion
IncompleteGamma
Incomplete Gamma Function
$\Gamma(a,z)$
The Incomplete function is defined by
the integral $\Gamma(a,z)=\int_{z}^{\infty} e^{-t}t^{a-1}dt$.
It has a branch cut along the negative real axis in the complex
$z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [6.5.3]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
Beta
Beta Function
$B(z,w)$
The Euler beta function is defined as
$B(z,w)=\int_{0}^{1} t^{z-1} (1-t)^{w-1} dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [6.2.1]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$B(z, w)=\frac{\Gamma(z)(w)}{\Gamma(z+w)}=B(w, z)$
IncompleteBeta
Incomplete Beta Function
$B_{z}(a,b)$
The incomplete Euler beta function is defined as
$B_{z}(a,b)=\int_{0}^{z} t^{a-1} (1-t)^{b-1} dt$.
It has a branch cut along the negative real axis in the complex
$z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [6.6.1]
Function
(real, real, real) $\rightarrow$ real
(real, complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$I_{x}(a, b)=B_{x}(a, b)/B(a, b)$
$I_{x}(a, b)=1-I_{1-x}(b, a)$, symmetry
$B_{z}(a, b)=a^{-1}z^aF(a, 1-b;a+1;z)$, relation to
hypergeometric function
erf
Error Function
$erf(z)$
The error function $erf(z)=\frac{2}{\sqrt{\pi}}\int_{0}^{z}e^{-t^2}dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [7.1.1]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$erf(-z)=-erf(z)$, symmetry
$erf \bar{z}=\overline {erf(z)}$,
symmetry
erfc
Complementary Error Function
$erfc(z)$
The complementary error function is defined by $erfc(z)=1-erf(z)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [7.1.2]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
FresnelC
Fresnel Integral Cosine
$C(z)$
The Fresnel integral is defined by
$C(z)=\int_{0}^{z} cos(\frac{\pi}{2} t^2) dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [7.3.1]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$C(z)=\sum_{n=0}^{\infty} \frac{(-1)^n(\pi /2)^{2n}}
{(2n)!(4n+1)}z^{4n+1}$, series expansion
$C(-z)=-C(z)$, symmetry
$C(iz)=iC(z)$, symmetry
$C(\bar{z})=\overline{C(z)}$, symmetry
FresnelS
Fresnel Integral Sine
$S(z)$
The Fresnel integral $S(z)$ is defined by
$S(z)=\int_{0}^{z} sin(\frac{\pi}{2}t^2)dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [7.3.2]
Function
real $\rightarrow$ real
complex $\rightarrow$ complex
symbolic $\rightarrow$ symbolic
$S(z)=\sum_{n=0}^{\infty} \frac{(-1)^n(\pi /2)^{2n+1}}
{(2n+1)!(4n+3)}z^{4n+3}$, series expansion
$S(-z)=-S(z)$, symmetry
$S(iz)=-iS(z)$, symmetry
$S(\bar{z})=\overline{S(z)}$, symmetry
LegendreP
Legendre Function of First Kind
$P_{\nu}(z)$
The Legendre function $P_{\nu}(z)= F(-\nu, \nu+1;1;
\frac{1-z}{2})$ is single-valued analytic function in z-plane
excludes z on the real axis from $-\infty$ to $-1$. It satisfies
the differential equation
$(1-z^2)\frac{d^2w}{dz^2}-2z\frac{dw}{dz}+[\nu(\nu+1)
-\frac{\mu^{2}}{1-z^2}]w=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [8.1.2]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
LegendreQ
Legendre Function of Second Kind
$Q_{\nu}(z)$
The Legendre function of second kind $Q_{\nu}(z)$. It is
analytic single-valued function in z-plane excludes z on the real
axis from $-\infty$ to 1.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [8.1.2]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
AssociatedLegendreP
Associated Legendre Function of First Kind
$P_{\nu}^{\mu}(z)$
The associated Legendre function $P_{\nu}^{\mu}(z)$
is defined by $P_{\nu}^{\mu}(z)=\frac{1}{\Gamma(1-\mu)}
(\frac{z+1}{z-1})^{\frac{1}{2}\mu}F(-\nu, \nu+1; 1-\mu; \frac{1-z}{2})$
where $F(a, b; c;z)$ is a hypergeometric function and $|1-z|\lt2$.
When $\mu=0$, It reduces to the Legendre function of the first
kind $P_{\nu}(z)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [8.1.2]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$P_{-\nu-1}^{\mu}(z)=P_{\nu}^{\mu}(z)$
AssociatedLegendreQ
Associated Legendre Function of Second Kind
$Q_{\nu}^{\mu}(z)$
The associated Legendre function is defined by
$Q_{\nu}^{\mu}(z)=e^{i\mu\pi}2^{-\nu-1}\sqrt{\pi}
\frac{\Gamma(\nu+\mu+1)}{\Gamma(\nu+\frac{3}{2})} z^{-\nu-\mu-1}
(z^2-1)^{\frac{1}{2}\mu} F(1+\frac{\nu}{2}+\frac{\mu}{2},
\frac{1}{2}+\frac{\nu}{2}
;\nu+\frac{3}{2}; \frac{1}{2})$ where $|z|>1$.
When $\mu=0$, It reduces to
the Legendre function of the second
kind $Q_{\nu}(z)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [8.1.3]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$P_{-\nu-1}^{\mu}(z)=P_{\nu}^{\mu}(z)$
$Q_{-\nu-1}^{\mu}(z)={-\pi e^{i\mu\pi} cos\nu \pi P_{\nu}^{\mu}(z)
+Q_{\nu}^{\mu}sin[\pi (\nu+\mu)]}/sin[\pi (\nu-\mu)]$
BesselJ
Bessel Functions of Integer Order
$J_{\nu}(z)$
The solutions to the differential equation $J_{\pm \nu}(z)$
$z^2 \frac{d^2w}{dz^2}+z\frac{dw}{dz} + (z^2-\nu^2)w=0$
are the Bessel functions of the first kind. It has a branch cut along
the negative real axis in the complex $z$ plane. When $\nu=\pm n$,
it is analytic in the entire complex z plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$J_{\nu}(z)=\sum_{k=0}^{\infty}
\frac{(-)^k}{k!\Gamma(\nu+k+1)}(\frac{z}{2})^{\nu+2k}$,
$|arg z|\lt \pi$, ascending series
$J_n^(z)=\frac{1}{\pi} \int_0^{\pi} cos(n \theta-
zsin \theta) d \theta$, integral representation
$J_{-n}(z)=(-1)^nJ_n(z)$, symmetry
$J^{\prime}_0(z)=-J_1(z)$, derivative
BesselY
Bessel Functions
$Y_{\nu}(z)$
$Y_{\nu}(z)$ are the second kind of Bessel functions. They are defined
in terms of first kind of Bessel functions as
$Y_{\nu}(z)=\frac{J_{\nu}(z)cos(\nu\pi)-J_{-\nu}(z)}{sin(\nu\pi)}$.
It has a branch cut along the negative real axis in the complex
$z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.1.2]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$Y_{-n}(z)=(-1)^nY_n(z)$, symmetry
$Y^{\prime}_0(z)=-Y_1(z)$, derivative
HankelH1
Hankel Functions
$H_{\nu}^{(1)}(z)$
The Hankel function $H_{\nu}^{(1)}(z)$ is one of the third kind of
Bessel function. It is defined by $H_{\nu}^{(1)}(z)=J_{\nu}(z) +iY_{\nu}(z)$.
It has a branch cut along the negative real axis in
the complex $z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.1.3]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
HankelH2
Hankel Functions
$H_{\nu}^{(2)}(z)$
The Hankel function $H_{\nu}^{(2)}(z)$ is one of the third kind of
Bessel function. It is defined by
$H_{\nu}^{(1)}(z)=J_{\nu}(z)-iY_{\nu}(z)$. It has a branch cut
along the negative real axis in the complex $z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.1.4]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
BesselI
Modified Bessel Functions
$I_{\nu}(z)$
The $I_{\pm\nu}(z)$ are the solutions of the differential equation
$z^2\frac{d^2w}{d^2z}+z\frac{dw}{dz}-(z^2+\nu^2)w=0$.
They are the modified Bessel functions of the first kind.
It has a branch cut along the negative real axis in the complex
$z$ plane. When $\nu=\pm n$, $I_{\nu}$ is an entire function of z.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.6.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$I_{\nu}(z)=\sum_{k=0}^{\infty} \frac{1}{k!\Gamma(\nu+k+1)}
(\frac{z}{2})^{2k+\nu}$, ascending series
$I_{-n}(z)=I_n(z)$
BesselK
Modified Bessel Functions
$K_{\nu}(z)$
The $K_{\nu}(z)$ are the solutions of the differential equation
$z^2\frac{d^2w}{d^2z}+z\frac{dw}{dz}-(z^2+\nu^2)w=0$.
They are the modified Bessel functions of the second kind.
It has a branch cut along the negative real axis in the complex
$z$ plane.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.6.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$K_{\nu}(z)=\frac{1}{2}\pi \frac{I_{-\nu}(z)-I_{\nu}(z)}
{sin(\nu\pi)}$, relation to $I_{\nu}(z)$
$\sqrt{\frac{\pi}{2z}}K_{n+\frac{1}{2}}(z)=
\frac{1}{2}\pi(-1)^{n+1} \sqrt{\frac{\pi}{2z}} [I_{n+\frac{1}{2}}(z)
-I_{-n-\frac{1}{2}}(z)]$, relation to $I_{\nu}(z)$
$K_{-\nu}(z)=K_{\nu}(z)$
SphericalBesselj
Spherical Bessel Functions
$j_{n}(z)$
The $j_{n}(z)$ are the spherical Bessel functions of the
first kind.
It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2-n(n+1)]w=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [10.1.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$j_{n}(z)=\sqrt{\frac{1}{2}\pi/z}J_{n+\frac{1}{2}}(z)$
SphericalBessely
Spherical Bessel Functions
$y_{n}(z)$
The $y_{n}(z)$ are the spherical Bessel functions of the
second kind.
It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2-n(n+1)]w=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [10.1.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$y_{n}(z)=\sqrt{\frac{1}{2}\pi/z}Y_{n+\frac{1}{2}}(z)$
SphericalHankel1
Spherical Hankel Functions
$h_{n}^{(1)}(z)$
The $h_{n}^{(1)}(z)$ are the spherical Bessel
functions of the
third kind.
It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2-n(n+1)]w=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [10.1.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$h_{n}^{(1)}(z)=\sqrt{\frac{1}{2}\pi/z}H_{n+\frac{1}{2}}
^{(1)}(z)$
SphericalHankel2
Spherical Hankel Functions
$h_{n}^{(2)}(z)$
The $h_{n}^{(2)}(z)$ are the spherical Bessel functions of the
third kind. It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2-n(n+1)]w=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [9.1]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$h_{n}^{(2)}(z)=\sqrt{\frac{1}{2}\pi/z}H_{n+\frac{1}{2}}
^{(2)}(z)$
ModifiedSphericalBesselI1
Modified Spherical Bessel Functions
$I_{n+\frac{1}{2}}(z)$
The $I_{n+\frac{1}{2}}(z)$ are the modified spherical Bessel functions
of the first kind. It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2+n(n+1)]w=0$ where $n \geq 0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [10.2.2]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$\sqrt{\frac{1}{2} \pi/z} I_{n+\frac{1}{2}}(z)=
e^{-n \pi i/2}j_n(ze^{\pi i/2})$, (-$\pi \le argz \leq \pi/2$)
ModifiedSphericalBesselI2
Modified Spherical Bessel Functions
$I_{-n-\frac{1}{2}}(z)$
The $I_{-n-\frac{1}{2}}(z)$ are the modified
spherical Bessel functions of the
second kind. It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2+n(n+1)]w=0$ where $n \geq 0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [10.2.3]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$\sqrt{\frac{1}{2} \pi/z} I_{-n-\frac{1}{2}}(z)=
e^{3(n+1) \pi i/2}y_n(ze^{\pi i/2})$, (-$\pi \lt argz \leq \pi/2$)
ModifiedSphericalBesselK
Modified Spherical Bessel Functions
$K_{n+\frac{1}{2}}(z)$
The $K_{n+\frac{1}{2}}(z)$ are the modified spherical
Bessel functions of the third kind.
It satisfies the differential equation
$z^2 w^{\prime\prime}+2zw^{\prime}+[z^2+n(n+1)]w=0$ where $n \geq 0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [10.2.3]
Function
(integer, real) $\rightarrow$ real
(integer, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$\sqrt{\frac{1}{2} \pi/z} K_{n+\frac{1}{2}}(z)=
\frac{1}{2} \pi (-1)^{n+1}\sqrt{\frac{1}{2} \pi/z}[I_{n+\frac{1}{2}}
-I_{-n-\frac{1}{2}}]$
StruveH
Struve Function
$H_{\nu}(z)$
The Struve functions $H_{\nu}(z)$ satisfy the differential equation
$z^2 w^{\prime\prime}+zw^{\prime}+(z^2-\nu^2)w=
\frac{4(\frac{z}{2})^{\nu+1}}{\sqrt{\pi}\Gamma(\nu+\frac{1}{2})}$.
The general solution to this equation is $w=aJ_{\nu}(z)+bY_{\nu}(z)+H_{\nu}(z)$,
a and b are constants.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [12.1]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$H_{\nu}(z)=(\frac{z}{2})^{\nu+1}\sum_{k=0}^{\infty}
\frac{(-1)^k(\frac{1}{2}z)^{2k}}{\Gamma(k+\frac{3}{2})
\Gamma(k+\nu+\frac{3}{2})}$, series expansion
StruveL
Modified Struve Function
$L_{\nu}(z)$
The modified Struve function is defined by
$L_{\nu}(z)=-i e^{-\frac{i \nu \pi}{2}}H_{\nu}(iz)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [12.2]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$L_{\nu}(z)=(\frac{z}{2})^{\nu+1}\sum_{k=0}^{\infty}
\frac{(z/2)^{2k}}{\Gamma(k+\frac{3}{2})\Gamma(k+\nu+\frac{3}{2})}$, series
expansion
AngerJ
Anger Function
${\cal{J}}_{\nu}(z)$
The Anger function is defined by
${\cal{J}}_{\nu}(z)=\frac{1}{\pi}\int_{0}^{\pi}cos(\nu\theta-zsin\theta)d\theta$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [12.3.1]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
${\cal{J}}_{n}(z)=J_{n}(z)$, n integer
WeberE
Weber Function
$E_{\nu}(z)$
The Weber function is defined by
$E_{\nu}(z)=\frac{1}{\pi}\int_{0}^{\pi}sin(\nu\theta-zsin\theta)d\theta$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [12.3.3]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$sin(\nu \pi){\cal{J}}_{\nu}(z)=cos(\nu \pi)E_{\nu}(z)-E_{-\nu}(z)$,
relation between $E_{\nu}(z)$ and ${\cal{J}}_{\nu}(z)$
$sin(\nu \pi)E_{\nu}(z)={\cal{J}}_{-\nu}(z)-cos(\nu \pi)
{\cal{J}}_{\nu}(z)$, relation between $E_{\nu}(z)$ and ${\cal{J}}_{\nu}(z)$
$E_{0}(z)=-H_{0}(z)$, relation between $E_{\nu}(z)$
and $H_{\nu}(z)$
$E_{1}(z)=\frac{2}{\pi}-H_{1}(z)$, relation between $E_{\nu}(z)$ and
$H_{\nu}(z)$
$E_{2}(z)=\frac{2z}{3 \pi}-H_{2}(z)$, relation between $E_{\nu}(z)$ and
$H_{\nu}(z)$
KummerM
Kummer Function
$M(a, b, z)$
The Kummer function KummerM satisfies the differential
equation $z w^{\prime\prime}+(b-z)w^{\prime}-aw=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [13.1.1]
Function
(real, real, real) $\rightarrow$ real
(real, real, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$M(a, b, z)=e^z M(b-a, b, -z)$, Kummer transformation
KummerU
Kummer Function
$U(a, b, z)$
The Kummer function KummerU satisfies the differential
equation $z w^{\prime\prime}+(b-z)w^{\prime}-aw=0$. Its principal branch is given by
$-\pi \lt argz \leq \pi$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [13.1.3]
Function
(real, real, real) $\rightarrow$ real
(real, real, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$U(a, 1-n, z)=z^nU(a+n, 1+n, z)$
$U(a, b, z)=\frac{\pi}{sin \pi b} \{\frac{M(a, b, z)}{\Gamma(1+a-b)
\Gamma(b)}-z^{1-b}\frac{M(1+a-b, 2-b, z)}{\Gamma(a)\Gamma(2-b)}\}$,
relation between KummerU and KummerM
$U(a, b, z)=z^{1-b}U(1+a-b, 2-b, z)$, Kummer transformation
WhittakerM
Whittaker Function
$M_{k,\mu}(z)$
The Whittaker's function WhittakerM satisfies the
Whittaker's equation $w^{\prime\prime}+[-\frac{1}{4}+\frac{k}{z}+\frac{(\frac{1}{4}
-\mu^2)}{z^2}]w=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [13.1.32]
Function
(real, real, real) $\rightarrow$ real
(real, real, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
Ying: what did you mean here? relation to KummerM
WhittakerW
Whittaker Function
$W_{k,\mu}(z)$
The Whittaker's function WhittakerW satisfies the
Whittaker's equation $w^{\prime\prime}+[-\frac{1}{4}+\frac{k}{z}+\frac{(\frac{1}{4}
-\mu^2)}{z^2}]w=0$ .
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [13.1.33]
Function
(real, real, real) $\rightarrow$ real
(real, real, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$W_{k, \mu}(z)=e^{-\frac{1}{2}z}z^{\frac{1}{2}+\mu}
U(\frac{1}{2}+\mu-k, 1+2\mu, z)$, $-\pi \lt argz \leq \pi$, $k=\frac{1}{2}b-a$,
$\nu=\frac{b}{2}-\frac{1}{2}$, relation to KummerU
CoulombWaveF
Regular Coulomb Wave Function
$F_L(\eta,\rho)$
The regular coulomb wave function CoulombWaveF
satisfies the Coulomb wave equation
$\frac{d^2w}{d^2 \rho}+[1-\frac{\eta}{\rho}-\frac{L(L+1)}{\rho^2}]w=0$ where
$\rho \gt0$, $-\infty \lt\eta\lt\infty$ and L is a non-negative integer.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [14.1.3]
Function
(integer, real, real) $\rightarrow$ real
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$F_L(\eta, \rho)=C_L(\eta)\rho^{L+1}e^{-i\rho}M(L+1-i\eta, 2L+2,
2i\rho)$, relation to KummerM
CoulombWaveG
Irregular Coulomb Wave Function
$G_L(\eta,\rho)$
The irregular Coulomb wave function CoulombWaveG satisfies the
Coulomb wave equation
$\frac{d^2w}{d^2 \rho}+[1-\frac{\eta}{\rho}-\frac{L(L+1)}{\rho^2}]w=0$ where $\rho \gt0$,
$-\infty \lt\eta\lt\infty$ and L is a non-negative integer.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [14.1.14]
Function
(integer, real, real) $\rightarrow$ real
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$G_L(\eta, \rho)=\frac{2\eta}{C_0^2(\eta)}F_L(\eta, \rho)
[ln2\rho+\frac{q_L(\eta)}{p_L(\eta)}]+\theta_L(\eta, \rho)$,
$\theta_L(\eta, \rho)=D_L(\eta)\rho^{-L}\psi_L(\eta, \rho)$,
$D_L(\eta)C_L(\eta)=\frac{1}{2L+1}$,
$\psi_L(\eta, \rho)=\sum_{k=-L}^{\infty}
a_k^L(\eta) \rho^{k+L}$
HypergeometricF
Hypergeometric Function (Gauss Series)
$F(a, b; c; z)$
The hypergeometric function $F(a, b; c; z)$ is the solution
of the hypergeometric differential equation
$z(1-z)w^{\prime\prime}+[c-(a+b+1)z]w^{\prime}-abw=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [15.1.1]
Function
(real, real, real, real) $\rightarrow$ real
(complex, complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic, symbolic) $\rightarrow$ symbolic
$F(1, 1; 2; z)=-z^{-1}ln(1-z)$, special case
$F(\frac{1}{2}, 1; \frac{3}{2}; z^2)=\frac{1}{2}z^{-1}ln\frac{(1+z)}{(1-z)}$
$F(\frac{1}{2}, 1; \frac{3}{2}; -z^2)=z^{-}arctanz$, special case
theta1
Theta Function
$\theta_1(z, q)$
The Jacobi theta function theta1 is defined by
$\theta_1(z, q)=2 q^{\frac{1}{4}}\sum_{n=0}^{\infty} (-1)^n q^{n(n+1)} sin(2n+1)z$
where $|q|\lt1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [16.27.1]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
theta2
Theta Function
$\theta_2(z, q)$
The Jacobi theta function theta2 is defined by
$\theta_2(z, q)=2 q^{\frac{1}{4}}\sum_{n=0}^{\infty} q^{n(n+1)} cos(2n+1)z$
where $|q|\lt1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [16.27.2]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
theta3
Theta Function
$\theta_3(z, q)$
The Jacobi theta function theta3 is defined by
$\theta_3(z, q)=1+2 \sum_{n=1}^{\infty} q^{n^2} cos2nz$ where $|q|\lt1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [16.27.3]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
theta4
Theta Function
$\theta_4(z, q)$
The Jacobi theta function theta4 is defined by
$\theta_4(z, q)=1+2 \sum_{n=1}^{\infty} (-1)^n q^{n^2} cos2nz$ where $|q|\lt1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [16.27.4]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
EllipticF
Elliptic Integral of The First Kind
$F(\phi\backslash \alpha)$
The elliptic integral of the first kind is defined by
$F(\phi\backslash \alpha)=F(\phi|m)=\int_0^{\phi}(1-sin^2\alpha sin^2\theta)
^{-\frac{1}{2}}d\theta$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [17.2.6]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
EllipticE
Elliptic Integral of The Second Kind
$E(\phi\backslash \alpha)$
The elliptic integral of the second kind is defined by
$E(\phi\backslash \alpha)=F(u|m)=\int_0^x(1-t^2)^{-\frac{1}{2}}
(1-mt^2)^{\frac{1}{2}}dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [17.2.8]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
EllipticPi
Elliptic Integral of The Third Kind
$\Pi(n; \phi \backslash \alpha)$
The elliptic integral of the third kind is defined by
$\Pi(n; \phi \backslash \alpha)=\int_0^{\phi}(1-nsin^2\theta)^{-1}
[1-sin^2\alpha sin^2\theta]^{-1/2} d\theta$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [17.2.14]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
EllipticK
Complete Elliptic Integral of The First Kind
$K(m)$
The complete elliptic integral of the first
kind $[K(m)]=K=\int_0^1[(1-t^2)(1-mt^2)]^{-\frac{1}{2}}dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [17.2.6]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
EllipticEK
Complete Elliptic Integral of The Second Kind
$E[K(m)]$
The complete elliptic integral of the second
kind $E[K(m)] = \int_0^1 (1-t^2)^{-\frac{1}{2}} (1-mt^2)^{\frac{1}{2}}dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [17.2.6]
Function
(real, real) $\rightarrow$ real
(complex, complex) $\rightarrow$ complex
(symbolic, symbolic) $\rightarrow$ symbolic
$K=F(\frac{\pi}{2}|m)$
WeierstrassP
Weierstrass $\wp$-Function
$\wp(z)$
The WeierstrassP($z;g_2, g_3$) is a single-valued doubly periodic
function with periods $2w$, $2 w^{\prime}$. $g_2$ and $g_3$ are invariants
which are related to $w$ and $w^{\prime}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [18.1]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
WeierstrassPPrime
Weierstrass $\wp^{\prime}$-Function
$\wp^{\prime}(z)$
The WeierstrassPPrime($z;g_2, g_3$) elliptic function is
defined by $\wp^{\prime}=\frac{\partial}{\partial{z}} \wp (z; g_2, g_3)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [18.1]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
WeierstrassZeta
Weierstrass $\zeta$-Function
$\zeta(z)$
The WeierstrassZeta($z;g_2, g_3$) function
satisfies the differential equation $\zeta^{\prime}(z)=- \wp (z)$. $\zeta(z)$ is not
an elliptic function.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [18.1]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
WeierstrassSigma
Weierstrass $\sigma$-Function
$\sigma(z)$
The WeierstrassSigma($z;g_2, g_3$) function satisfies the condition
$\frac{\sigma^{\prime}(z)}{\sigma(z)}=\zeta(z)$. It is not an elliptic function.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [18.1]
Function
(real, real, real) $\rightarrow$ real
(complex, complex, complex) $\rightarrow$ complex
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
MathieuC
even Mathieu functions
$y(a,q,z)$
The MathieuC functions are solutions to the Mathieu's equation
$\frac{d^2y}{dz^2}+(a-2qcos(2z))y=0$. This function is defined
to be even in z.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [20.1.1]
Function
( real, real, real) $\rightarrow$ real
( symbolic, symbolic, symbolic) $\rightarrow$ symbolic
MathieuS
odd Mathieu functions
$y(a,q,z)$
The MathieuS functions are solutions to the Mathieu's equation
$\frac{d^2y}{dz^2}+(a-2qcos(2z))y=0$. This function is defined
to be odd in z.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [20.1.1]
Function
( real, real, real) $\rightarrow$ real
( symbolic, symbolic, symbolic) $\rightarrow$ symbolic
MathieuCharacteristicValuesA
characteristic values for even Mathieu functions
$a_r(q)$
A countably infinite set of characteristic values $a_r(q)$ yield
even periodic solutions to the Mathieu's equation
$\frac{d^2y}{dz^2}+(a-2qcos(2z))y=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [20.1]
Function
( real, real, real) $\rightarrow$ real
( symbolic, symbolic, symbolic) $\rightarrow$ symbolic
MathieuCharacteristicValuesB
characteristic values for odd Mathieu functions
$b_r(q)$
A countably infinite set of characteristic values $b_r(q)$ yield
odd periodic solutions to the Mathieu's equation
$\frac{d^2y}{dz^2}+(a-2qcos(2z))y=0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [20.1]
Function
( real, real, real) $\rightarrow$ real
( symbolic, symbolic, symbolic) $\rightarrow$ symbolic
JacobiP
Jacobi Polynomials
$P_n^{(\alpha,\beta)}(x)$
The Jacobi polynomials $P_n^{(\alpha,\beta)}(x)$ satisfy the generating
function relation $R^{-1}(1+z+R)^{-\alpha}(1+z+R)^{-\beta}
=\sum_{n=0}^{\infty} 2^{-\alpha-\beta} P_n^{(\alpha, \beta)}(x)z^n$
where $R=\sqrt{1-2xz+z^2}$ and $|z|\lt1$. The explicit expression of
Jacobi polynomials $P_n^{(\alpha,\beta)}(x)$ is written as
$P_n^{(\alpha,\beta)}(x)=\frac{1}{2^n}\sum_{m=0}^n
{n+\alpha \choose m}{n+\beta \choose n-m}(x-1)^{n-m}(x+1)^m$ where ($\alpha>-1$,
$\beta\gt-1$) .
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.9.1], [22.3.1]
Function
(integer, real, real, real) $\rightarrow$ real
(symbolic, symbolic, symbolic, symbolic) $\rightarrow$ symbolic
UltrasphericalC
Ultraspherical Polynomials
$C_n^{(\alpha)}(x)$
The ultraspherical polynomials satisfy the generating function relation
$R^{-2 \alpha}=\sum_{n=0}^{\infty} C_n^{(\alpha)}(x) z^n$ where $R=\sqrt{1-2xz+z^2}$
and $|z|\lt1$. The explicit expressions for the Ultraspherical
polynomials can be written as
$C_n^{(\alpha)}(x)=\frac{1}{\Gamma{(\alpha})} \sum_{m=0}^{[\frac{n}{2}]}
(-1)^m \frac{\Gamma(\alpha+n-m)}{m!(n-2m)!} (2x)^{n-2m}$ where
$\alpha>-\frac{1}{2}$ and $\alpha\neq 0$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.3.4]
Function
Function
(integer, real, real) $\rightarrow$ real
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
ChebyshevT
Chebyshev Polynomials
$T_n(x)$
The Chebyshev polynomials of the first kind $T_n(x)$ satisfy the
generating function relation $\frac{1-xz}{R^2}=T_n(x)z^n$
where $|x|\lt1$ and $|z|\lt1$. The explicit Chebyshev polynomials can be written
as $T_n(x)=\frac{n}{2} \sum_{m=0}^{[\frac{n}{2}]} (-1)^m
\frac{(n-m-1)!}{m!(n-2m)!} (2x)^{n-2m}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.9.9], [22.3.6]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
ChebyshevU
Chebyshev Polynomials
$U_n(x)$
The Chebyshev polynomials of the second kind
$U_n(x)$ satisfy the generating function relation $R^{-2}=\sum_{n=0}^{\infty}
U_n(x)z^n$ where $|x|\lt1$ and $|z|\lt1$.
The explicit expression can be written
as $U_n(x)=\sum_{m=0}^{[\frac{n}{2}]} (-1)^m
\frac{(n-m)!}{m!(n-2m)!} (2x)^{n-2m}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.9.10], [22.3.7]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
LegendreP
Legendre Polynomials
$P_n(x)$
The Legendre polynomials satisfy the generating function relation
$R^{-1}=\sum_{n=0}^{\infty} P_n(x) z^n$ where $|x|\lt1$ and $|z|\lt1$.
The explicit expression for Legendre
polynomials can be written as $P_n(x)=\frac{1}{2^n}
\sum_{m=0}^{[\frac{n}{2}]} (-1)^m {n \choose m}{2n-2m \choose n} x^{n-2m}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.9.12], [22.3.8]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
LaguerreL
Laguerre Polynomials
$L_n^{(\alpha)}(x)$
The Leguerre polynomials $L_n^{(\alpha)}(x)$
satisfy the generating function relation $(1-z)^{-\alpha-1}exp(\frac{xz}
{z-1})=\sum_{n=0}^{\infty} L_n^{\alpha}(x) z^n$ where $|z|\lt1$.
Its explicit expression can be written as $L_n^{(\alpha)}(x)=\sum_{m=0}^n
(-1)^m {n+\alpha \choose n-m} \frac{1}{m!} x^m$ where $\alpha>-1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.9.15], [22.3.9]
Function
(integer, real, real) $\rightarrow$ real
(symbolic, symbolic, symbolic) $\rightarrow$ symbolic
HermiteH
Hermite Polynomials
$H_n(x)$
The Hermite polynomial satisfy the generating
function relation $ e^{2xz-z^2}=\sum_{n=0}^{\infty} \frac{1}{n!} H_n(x) z^n$.
The explicit expressions for Hermite polynomials
can be written as $H_n(x)=n!\sum_{m=0}^{[\frac{n}{2}]}
(-1)^m \frac{1}{m!(n-2m)!} (2x)^{n-2m}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [22.9.17], [22.3.10]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
Zeta
Riemann Zeta Function
$\zeta(s)$
The Riemann zeta function is defined by
$\zeta(s)=\sum_{k=1}^{\infty} k^{-s}$ where $\Re{s}>1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.2.1]
Function
real $\rightarrow$ real
complex $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$\zeta(0)=-\frac{1}{2}$, special value
$\zeta(1)=\infty$, special value
$\zeta^{\prime}(0)=-\frac{1}{2} ln(2 \pi)$, special value
$\zeta(-2n)=0$, $n=1,2, \dots$, special value
$\zeta(1-2n)=-\frac{B_{2n}}{2n}$, $n=1, 2, \dots$, special value
$\zeta(2n)=\frac{(2 \pi)^{2n}}{2(2n)!}|B_{2n}|$,
$n=1, 2, \dots$, special value
$\zeta(2n+1)=\frac{(-1)^{n+1}(2 \pi)^{2n+1}}{2(2n+1)!}
\int_0^1B_{2n+1}(x)cot(\pi x) dx$, $n=1, 2, \dots$, special value
$\zeta(2)=1+\frac{1}{2^2}+\frac{1}{3^2}+\dots
=\frac{\pi^2}{6}$, special value
$\zeta(4)=1+\frac{1}{2^4}+\frac{1}{3^4}+\dots
=\frac{\pi^4}{90}$, special value
BernoulliB
Bernoulli Polynomials
$B_n(x)$
The Bernoulli polynomials $B_n(x)$ satisfy the generating
function relation $\frac{te^{xt}}{e^t-1}=\sum_{n=0}^{\infty}B_n(x)\frac{t^n}{n!}$
where $|t|\lt2 \pi$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [23.1.1]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
$B^{\prime}_{n}(x)=nB_{n-1}(x)$, $n=1,2,\dots$, derivative
$B_n(x+1)-B_n(x)=nx^{n-1}$, $n=0,1,2,\dots$, difference
$B_n(1-x)=(-1)^nB_n(x)$, $n=0,1,2,\dots$, symmetry
$(-1)^n B_n(-x)=B_n(x)+nx^{n-1}$, $n=0,1,2,\dots$, symmetry
$B_{2n+1}=0$, $n=1, 2, \dots$, special value
$B_n(0)=(-1)^n B_n(1)=B_n$, $n=0, 1, \dots$, special value
$B_n(\frac{1}{2})=-(1-2^{1-n})B_n$, $n=0, 1, \dots$, special value
$B_n(\frac{1}{4})=(-1)^n B_n(\frac{3}{4})$, $n=1, 2, \dots$, special value
$B_{2n}(\frac{1}{3})=B_{2n}(\frac{2}{3})$, $n=0, 1,
\dots$, special value
$B_{2n}(\frac{1}{6})=B_{2n}(\frac{5}{6})$,
$n=0, 1, \dots$, special value
BernoulliBn
Bernoulli Numbers
$B_n$
The Bernoulli number $B_n$ is defined as $B_n=B_n(0)$
where $n=0,1,2, \dots$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [23.1.2]
Constant
$B_0=1$
$B_1=-\frac{1}{2}$
$B_2=\frac{1}{6}$
$B_4=-\frac{1}{30}$
EulerE
Euler Polynomials
$E_n(x)$
The Euler polynomials $E_n(x)$ satisfy the generating
function relation $\frac{2e^{xt}}{e^t+1}=\sum_{n=0}^{\infty}E_n(x)
\frac{t^n}{n!}$ where $|t|\lt\pi$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [23.1.1]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
$E^{\prime}_n(x)=nE_{n-1}(x)$, $n=1,2,\dots$, derivative
$E_n(x+1)+E_n(x)=2x^n$, $n=0,1,\dots$, difference
$E_n(1-x)=(-1)^nE_n(x)$, $n=0,1,\dots$, symmetry
$(-1)^{n+1}E_{n}(-x)=E_{n}(x)-2x^n$, $n=0,1,\dots$, symmetry
$E_{2n+1}=0$, $n=0, 1, \dots$, special value
$E_n(0)=-E_n(1)$, $n=1, 2, \dots$, special value
$E_n(\frac{1}{2})=2^{-n}E_n$, $n=0, 1, \dots$, special value
$E_{2n-1}(\frac{1}{3})=-E_{2n-1}(\frac{2}{3})$, $n=1, 2, \dots$, special value
EulerE
Euler Numbers
$E_n$
The Euler number $E_n$ is defined as $E_n=2^nE_n (\frac{1}{2})$
where $n=0,1,2,\dots$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [23.1.2]
Constant
$E_0=1$
$E_2=-1$
$E_4=5$
Binomial
Binomial Coefficients
${n \choose m} $
The definition for the binomial coefficient ${n \choose m} $ is the number
of ways of choosing m objects from a collection of n
distinct objects without regard to order. It satisfies the generating
function relation $(1+x)^n=\sum_{m=0}^n {n \choose m} x^m$ where $n=0,1,2,\dots$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.1.1]
Function
(integer, integer) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
${n \choose m}=\frac{n!}{m!(n-m)!}={n \choose n-m}$, $n \geq m$
${n+1 \choose m}={n \choose m}+ {n \choose m-1}$,
$n\geq m\geq 1$, recurrence relation
$\sum_{m=0}^n {r \choose m}{s \choose n-m}=
{r+s \choose n}$, $r+s \geq n$, check relation
$\sum_{m=0}^n (-1)^{n-m}
{r \choose m}={r-1 \choose n}$, $r \geq n+1$, check relation
${n \choose 0}={n \choose 0}=1$, special value
${2n \choose n}=\frac{2^n(2n-1)(2n-3) \dots 3 \cdot 1}{n!}$, special value
Multinomial
Multinomials
$(n;n_1,n_2,\dots, n_m)$
The multinomial coefficients $ (n;n_1,n_2,\dots, n_m)$ satisfy the generating
function relation $(x_1+x_2+\dots+x_m)^n=\Sigma(n;n_1,n_2,\dots, n_m)
x_1^{n_1}x_2^{n_2}\dots x_m^{n_m}$ summed over
$n_1+n_2+\dots+n_m=n$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.1.2]
Function
(integer, ..., integer) $\rightarrow$ real
(symbolic, ..., symbolic) $\rightarrow$ symbolic
$(n;n_1,n_2,\dots,n_m)=\frac{n!}{n_1!n_2! \dots n_m!}$
$(n+m;n_1+1, n_2+1, \dots, n_m+1)=\sum_{k=1}^m (n+m-1;n_1+1, \dots, n_{k-1}+1,
n_{k+1}+1, \dots, n_m+1)$,
recurrence relation
StirlingS1
Stirling Numbers of the First Kind
$S_n^{(m)}$
The Stirling Numbers of the first Kind $S_n^{(m)}$ satisfy
the generating function relation $x(x-1)\dots(x-n+1)=\sum_{m=0}^nS_n^{(m)}x^m$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.1.3]
Function
(integer, integer) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
$S_{n+1}^{(m)}=S_n^{(m-1)}-nS_n^{(m)}$, $n\geq m\geq1$, recurrence relation
${m \choose r}S_n^{(m)}=\sum_{k=m-r}^{n-r}{n \choose k}
S_{n-k}^{(r)}S_k^{(m-r)}$, $n\geq m\geq r$, recurrence relation
$\sum_{m=1}^n S_n^{(m)}=0$, $n >1$, check relation
$\sum_{m=0}^n (-1)^{n-m} S_n^{(m)}=n!$, check relation
$\sum_{k=m}^n S_{n+1}^{(k+1)}n^{k-m}=S_n^{(m)}$, check relation
$S_n^{(0)}=\delta_{0n}$, special value
$S_n^{(1)}=(-1)^{n-1}(n-1)!$, special value
$S_n^{(n-1)}=-{n \choose 2}$, special value
$S_n^{(n)}=1$, special value
StirlingS2
Stirling Numbers of the Second Kind
${\cal{S}}_n^{(m)}$
The Stirling Numbers of the second kind ${\cal{S}}_n^{(m)}$ satisfy the generating
function relation $x^n=\sum_{m=0}^n{\cal{S}}_{n}^{(m)}x(x-1) \dots (x-m+1)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.1.4]
Function
(integer, integer) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
${\cal{S}}_n^{(m)}=\frac{1}{m!}\sum_{k=0}^m(-1)^{m-k} {m \choose k} k^n$
${\cal{S}}_{n+1}^{(m)}=m{\cal{S}}_n^{(m)}+{\cal{S}}_n^{(m-1)}$,
$n\geq m\geq 1$, recurrence relation
${m \choose r} {\cal{S}}_n^{(m)}=\sum_{k=m-r}^{n-r}
{n \choose k} {\cal{S}}_{n-k}^{(r)}{\cal{S}}_k^{(m-r)}$, recurrence relation
$\sum_{k=m}^n {\cal{S}}_k^{(m)} {\cal{S}}_n^{(k)}= \sum_{k=m}^n {\cal{S}}_n^{(k)}
{\cal{S}}_k^{(m)}=\delta_{mn}$, check relation
$\sum_{m=0}^n (-1)^{n-m}m! {\cal{S}}_n^{(m)}=1$, check relation
$\sum_{k=m}^n {\cal{S}}_{k-1}^{(m-1)}m^{n-k}={\cal{S}}_n^{(m)}$, check relation
${\cal{S}}_n^{(m)}=\sum_{k=0}^{n-m}(-1)^k {n-1+k \choose n-m+k} {2n-m \choose n-m-k}
{\cal{S}}_{n-m+k}^{(k)}$, check relation
${\cal{S}}_n^{(0)}=\delta_{0n}$, special value
${\cal{S}}_n^{(n-1)}={n \choose 2}$, special value
${\cal{S}}_n^{(1)}={\cal{S}}_n^{(n)}=1$, special value
PartitionsP
Unrestricted Partitions
$p(n)$
The number $p(n)$ of unrestricted partitions of the integer n is the number
of decompositions of n into integer summands without regard to order. For example,
$5=1+4=2+3=1+1+3=1+2+2=1+1+1+2=1+1+1+1+1$ so that $p(5)=7$. $p(n)$ satisfies the
generating function relation
$\sum_{n=0}^{\infty} p(n)x^n=\Pi_{n=1}^{\infty}(1-x^n)^{-1}$ where $|x|\lt1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.2.1]
Function
integer $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$p(n)=\frac{1}{n} \sum_{k=1}^n\sigma_1(k)p(n-k)$, recurrence relation
PartitionsQ
Unrestricted Partitions
$q(n)$
The number $q(n)$ of partitions of the integer n into distinct parts is the number
of decompositions of n into distinct integer summands without regard
to order. For example, $5=1+4=2+3$ so that $q(5)=3$. It satisfies the generating
function relation $\sum_{n=0}^{\infty}q(n)x^n=\Pi_{n=1}^{\infty}(1+x^n)=
\Pi_{n=1}^{\infty} (1+x^n)=\Pi_{n=1}^{\infty}(1-x^{2n-1})^{-1}$ where $|x|\lt1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.2.2]
Function
integer $\rightarrow$ real
symbolic $\rightarrow$ symbolic
MobiusMu
M$\ddot{o}$bius Functions
$\mu(n)$
The M$\ddot{o}$bius function $\mu(n)$ is defined to be 1 if $n=1$, $(-1)^k$ if
$n$ is the product of k distinct primes and 0 if n contains a square factor.
It satisfies the generatingi function relation
$\sum_{n=1}^{\infty} \mu(n) n^{-s}=\frac{1}{\zeta(s)}$ for $\Re{s}>1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.3.1]
Function
integer $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$\mu(mn)=\mu(m)\mu(n)$ if $(m,n)=1$, recurrence relation
$\mu(mn)=0$ if $(m,n)>1$, recurrence relation
$\sum_{d \backslash n}\mu(d)=\delta_{n1}$, check relation
$\sum_{n=1}^{\infty} \frac{\mu(n)}{n}=0$, asymptotics
$\sum_{n=1}^{\infty}\frac{\mu(n)}{n}lnn=-1$, asymptotics
EulerTotientPhi
Euler Totient Function
$\phi(n)$
The Euler Totient $\phi(n)$ function is number of integers not exceeding
and relatively prime to n. It satisfies the generating function relation
$\sum_{n=1}^{\infty} \phi(n)
n^{-s}=\frac{\zeta(s-1)}{\zeta(s)}$ where $\Re{s}>2$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.3.2]
Function
integer $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$\phi(n)=n\Sigma_{p \backslash n}(1-\frac{1}{p})$ over distinct primes p dividing n.
$\phi(mn)=\phi(m) \phi(n)$, $(m,n)=1$, recurrence relation
$\Sigma_{d \backslash n}\phi(d)=n$, check relation
$\phi(n)=\Sigma_{d \backslash n} \mu (\frac{n}{d})d$, check relation
$a^{(\phi(n))}\equiv 1(mod n)$, $(a,n)=1$
DivisorSigma
Divisor Function
$\sigma_k(n)$
The divisor function $\sigma_k(n)$ is the sum of the $k$-th powers of the
divisors of $n$. It satisfies the generating function relation
$\sum_{n=1}^{\infty} \sigma_k(n)
n^{-s}=\zeta(s)\zeta(s-k)$ where $\Re{s}>k+1$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [24.3.3]
Function
integer $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$\sigma_k(mn)=\sigma_k(m) \sigma_k(n)$, $(m,n)=1$, recurrence relation
$\sigma_{np}=\sigma_k(n) \sigma_k(p)-p^k \sigma_k(n/p)$, $p$ is prime,
recurrence relation
Debye
Debye Function
$f(x)$
The Debye functions are defined by $\int_0^x \frac{t^ndt}{e^t-1}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [27.1.1]
Function
(integer, real) $\rightarrow$ real
(symbolic, symbolic) $\rightarrow$ symbolic
$\int_0^x\frac{t^ndt}{e^t-1}=x^n [\frac{1}{n}-
\frac{x}{2(n+1)}+\sum_{k=1}^{\infty}\frac{B_{2k}x^{2k}}{(2k+n)(2k)!}]$
, ($|x|\lt2 \pi$, $n \geq 1$), series representation
$\int_0^{\infty}\frac{t^ndt}{e^t-1}=n!\zeta(n+1)$,
relation to Riemann Zeta function
PlanckRadiationFunc
Planck Radiation Function
$f(x)$
The Planck radiation function is defined by $f(x)=x^{-5}(e^{1/x}-1)^{-1}$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [27.2]
real $\rightarrow$ real
symbolic $\rightarrow$ symbolic
Function
SievertIntegral
Sievert Integral
$S(x)$
The Sievert Integral is defined by $\int_{0}^{\theta} e^{-xsec\phi} d\phi$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [27.4]
Function
real $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$\int_0^{\theta} e^{-xsec \phi}d\phi \sim \sqrt{\frac{\pi}{2}}e^{-x}
erf (\sqrt{\frac{x}{2}}\theta)$, ($x \rightarrow \infty$),
relation to error function
DilogarithmInt
Dilogarithm Integral
$f(x)$
The Dilogarithm integral is defined by $f(x)=-\int_{1}^{x} \frac{lnt}{t-1}dt$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [27.7]
Function
real $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$f(x)=\sum_{k=1}^{\infty} (-1)^k \frac{(x-1)^k}{k^2}$,
($2 \geq x \geq 0$), series expansion
ClausenInt
Clausen's Integral
$f(\theta)$
The Clausen integral is defined as $f(\theta)=-\int_{0}^{\theta}ln(2sin\frac{t}{2})dt
=\sum_{k=1}^{\infty}\frac{sink\theta}{k^2}$ $(0 \leq \theta \leq \pi)$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [27.8]
Function
real $\rightarrow$ real
symbolic $\rightarrow$ symbolic
$f(\pi-\theta)=f(\theta)-\frac{1}{2}f(2\theta)$,
$(0 \leq \theta \leq \frac{\pi}{2})$, functional relationship
$\sum_{n=1}^{\infty}\frac{cosn\theta}{n}=
-ln(2sin\frac{\theta}{2})$, ($0 \lt \theta \lt 2 \pi$), summable series
$\sum_{n=1}^{\infty}\frac{cosn\theta}{n^2}=
\frac{\pi^2}{6}-\frac{\pi \theta}{2}+\frac{\theta^2}{4}$, ($0 \leq \theta
\leq 2 \pi$), summable series
$\sum_{n=1}^{\infty}\frac{cosn\theta}{n^4}=
\frac{\pi^4}{90}-\frac{\pi^2 \theta^2}{12}+\frac{\pi \theta^3}{12}-
\frac{\theta^4}{48}$, ($0 \leq \theta \leq 2 \pi$), summable series
$\sum_{n=1}^{\infty}\frac{sin n \theta}{n}=
\frac{1}{2}(\pi-\theta)$, ($0 \lt \theta \lt 2 \pi$), summable series
$\sum_{n=1}^{\infty}\frac{sin n \theta}{n^3}=
\frac{\pi^2 \theta}{6}-\frac{\pi \theta^2}{4}+\frac{\theta^3}{12}$,
($0 \leq \theta \leq 2 \pi$), summable series
$\sum_{n=1}^{\infty}\frac{sin n \theta}{n^5}=
\frac{\pi^4 \theta}{90}-\frac{\pi^2 \theta^3}{36}+\frac{\pi \theta^4}{48}
-\frac{\theta^5}{240}$, ($0 \leq \theta \leq 2 \pi$), summable series
CGCoefficients
Clebsch-Gordan Coefficients
$(j_1j_2m_1m_2|j_1j_2jm)$
The Clebsch-Gordan Coefficients are defined by
$(j_1j_2m_1m_2|j_1j_2jm) = \\
\delta(m, m_1+m_2) \sqrt{\frac{(j_1+j_2-j)!(j+j_1-j_2)!(j+j_2-j_1)!(2j+1)}
{(j+j_1+j_2+1)!}} \cdot \Sigma_k \frac{(-1)^k\sqrt{(j_1+m_1)!(j_1-m_1)!
(j_2+m_2)!(j_2-m_2)!(j+m)!(j-m)!}}{k!(j_1+j_2-j-k)!
(j_1-m_1-k)!(j_2+m_2-k)!(j-j_2+m_1+k)!(j-j_1-m_2+k)!}$
where $\delta(m, m_1+m_2)=1$ when $m=m_1+m_2$ and 0 when $m \neq m_1+m_2$.
M. Abramowitz and I. Stegun, Handbook of
Mathematical Functions, [27.9.1]
Function
$j_1$, $j_2$, $j=+n$ or $+n/2$ ($n=integer$), condition
$j_1+j_2+j=n$, condition
$j_1+j_2-j \geq 0$, condition
$j_1-j_2+j \geq 0$, condition
$-j_1+j_2+j \geq 0$, condition
$m_1, m_2, m=\pm n$ or $\pm n/2$, condition
$|m_1|\leq j_1$, $|m_2|\leq j_2$, $|m|\leq j$, condition
$(j_1j_2m_1m_2|j_1j_2jm)=0$ $m_1+m_2 \neq 0$, condition
$(j_10m_10|j_10jm)=\delta(j_1, j) \delta(m_1, m)$, special value
$(j_1j_200|j_1j_2j0)=0$ $j_1+j_2+j=2n+1$, special value
$(j_1j_1m_1m_1|j_1j_1jm)=0$ $2j_1+j=2n+1$, special value
$(j_1j_2m_1m_2|j_1j_2jm)=(-1)^{j_1+j_2-j}(j_1j_2-m_1-m_2|j_1j_2j-m)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=(j_2j_1-m_2-m_1|j_2j_1j-m)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=(-1)^{j_1+j_2-j}
(j_2j_1m_1m_2|j_2j_1jm)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=\sqrt{\frac{2j+1}{2j_1+1}} (-1)^{j_2+m_2}
(jj_2-mm_2|jj_2j_1-m_1)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=\sqrt{\frac{2j+1}{2j_1+1}} (-1)^{j_1-m_1+j-m}
(jj_2m-m_2|jj_2j_1m_1)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=\sqrt{\frac{2j+1}{2j_1+1}} (-1)^{j-m+j_1-m_1}
(j_2jm_2-m|j_2jj_1-m_1)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=\sqrt{\frac{2j+1}{2j_2+1}} (-1)^{j_1-m_1}
(j_1jm_1-m|j_1jj_2-m_2)$, symmetry
$(j_1j_2m_1m_2|j_1j_2jm)=\sqrt{\frac{2j+1}{2j_2+1}} (-1)^{j_1-m_1}
(jj_1m-m_1|jj_1j_2m_2)$, symmetry