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