$$\Gamma \left(a\right)=\left(l^a{e}^{-l}\right)\left(\sum _{k=0}^{\infty }\frac{l^n}{a^{\stackrel{-}{k+1}}}+\frac{1}{l-a+1+\frac{c_1}{d_1+\frac{c_2}{d_2+\frac{c_3}{d_3+\dots }}}}\right);c_k=k\left(a-k\right)\wedge d_k=l-a+2k+1$$