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