\[I_{1}(x)=\mathscr{M}\mskip-3.0muh_{1}\mskip 3.0mu\left(1\right)x^{-1}+\frac{1}%
{2\pi i}\int_{\rho-i\infty}^{\rho+i\infty}x^{-z}\Gamma\left(1-z\right)\mathscr%
{M}\mskip-3.0muh_{1}\mskip 3.0mu\left(z\right)\,\mathrm{d}z,\]