# Hypergeometric 1F2

The hypergeometric ${}_1F_2$ is defined by the series $${}_1F_2(a;b,c;z)=\displaystyle\sum_{k=0}^{\infty} \dfrac{(a)_kz^k}{(b)_k(c)_k k!},$$ where $(a)_k$ denotes the Pochhammer symbol and $k!$ denotes the factorial.