# Ramanujan Divisor Function [closed]

Help me prove

$$\sum_{n=1}^\infty \frac{\sigma_a(n)\sigma_b(n)}{n^s} = \frac{\zeta(s) \zeta(s-a) \zeta(s-b) \zeta(s-a-b)}{\zeta(2s-a-b)}$$

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mathoverflow.net/howtoask –  Yemon Choi Aug 1 '12 at 7:44

## closed as too localized by Neil Strickland, Gerry Myerson, quid, Dan Petersen, Henry CohnAug 1 '12 at 16:53

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