Calculate-a-1-b-1-c-1-ab-3a-c-4-a-b-c-a-b-b-c-c-a-

Question Number 55920 by ANTARES VY last updated on 06/Mar/19

Calculate .

\underset{a = 1}{\sum^{\infty}} \underset{b = 1}{\sum^{\infty}} \underset{c = 1}{\sum^{\infty}} \frac{a b (3 a + c)}{4^{a + b + c} (a + b) (b + c) (c + a)} .

Commented by mr W last updated on 06/Mar/19

\frac{1}{54}

c a n s o m e o n e p r o v e ?

Facebook Tweet Pin