\[\operatorname{Bi}\left(z\right)=\frac{1}{3^{1/6}\Gamma\left(\tfrac{2}{3}\right%
)}e^{-\zeta}{{}_{1}F_{1}}\left(\tfrac{1}{6};\tfrac{1}{3};2\zeta\right)+\frac{3%
^{5/6}}{2^{2/3}\Gamma\left(\tfrac{1}{3}\right)}\zeta^{2/3}e^{-\zeta}{{}_{1}F_{%
1}}\left(\tfrac{5}{6};\tfrac{5}{3};2\zeta\right),\]