\[\mathbf{M}_{\nu}\left(z\right)\sim\frac{1}{\pi}\sum_{k=0}^{\infty}(-1)^{k+1}%
\frac{\Gamma\left(k+\tfrac{1}{2}\right)(\tfrac{1}{2}z)^{\nu-2k-1}}{\Gamma\left%
(\nu+\tfrac{1}{2}-k\right)},\]