3 ϕ 2 ( a , b , q - n c , a b q 1 - n / c ; q , q ) = ( c / a , c / b ; q ) n ( c , c / ( a b ) ; q ) n {{}_{3}\phi_{2}}\left({a,b,q^{-n}\atop c,abq^{1-n}/c};q,q\right)=\frac{\left(c/a,c/b;q\right)_{n}}{\left(c,c/(ab);q\right)_{n}}