\[h_{n}\left(x;q\right)=\left(q;q\right)_{n}\sum_{\ell=0}^{\left\lfloor n/2%
\right\rfloor}\frac{(-1)^{\ell}q^{\ell(\ell-1)}x^{n-2\ell}}{\left(q^{2};q^{2}%
\right)_{\ell}\left(q;q\right)_{n-2\ell}}=x^{n}{{}_{2}\phi_{0}}\left({q^{-n},q%
^{-n+1}\atop-};q^{2},x^{-2}q^{2n-1}\right).\]