\[\operatorname{Ai}\left(z\right)=\tfrac{1}{2}\pi^{-1/2}z^{-1/4}W_{0,1/3}\left(2%
\zeta\right)=3^{-1/6}\pi^{-1/2}\zeta^{2/3}e^{-\zeta}U\left(\tfrac{5}{6},\tfrac%
{5}{3},2\zeta\right),\]