\[{\mathbf{M}}\left(-a,b,z\right)\sim\left(z/a\right)^{(1-b)/2}\frac{e^{z/2}%
\Gamma\left(1+a\right)}{\Gamma\left(a+b\right)}\*\left(J_{b-1}\left(2\sqrt{az}%
\right)\sum_{s=0}^{\infty}\frac{p_{s}(z)}{(-a)^{s}}-\sqrt{z/a}J_{b}\left(2%
\sqrt{az}\right)\sum_{s=0}^{\infty}\frac{q_{s}(z)}{(-a)^{s}}\right),\]