( u − 1 ) ( v − 1 ) ( w − 1 ) ( w 2 − w + 1 ) 2 u v w 5 / 2 {\displaystyle {\frac {(u-1)(v-1)(w-1)\left(w^{2}-w+1\right)^{2}}{{\sqrt {u}}{\sqrt {v}}w^{5/2}}}}