p F q ( a 1 , . . . , a p ; c 1 , . . . , c q ; z ) = ∑ n = 0 ∞ ( a 1 ) n ⋅ ⋅ ⋅ ( a p ) n ( c 1 ) n ⋅ ⋅ ⋅ ( c q ) n z n n ! {\displaystyle {}_{p}F_{q}(a_{1},...,a_{p};c_{1},...,c_{q};z)=\sum _{n=0}^{\infty }{\frac {(a_{1})_{n}\cdot \cdot \cdot (a_{p})_{n}}{(c_{1})_{n}\cdot \cdot \cdot (c_{q})_{n}}}{\frac {z^{n}}{n!}}\,}