\[e^{-\frac{1}{2}y}\left(\frac{x+y}{x}\right)^{\mu+\frac{1}{2}}\sum_{n=0}^{%
\infty}\frac{{\left(\frac{1}{2}+\mu-\kappa\right)_{n}}}{{\left(1+2\mu\right)_{%
n}}n!}\left(\frac{y}{\sqrt{x}}\right)^{n}\*M_{\kappa-\frac{1}{2}n,\mu+\frac{1}%
{2}n}\left(x\right),\]