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6 votes
1 answer
484 views

Three conjectural series for $\pi^2$ and related identities

Recently, I found the following three (conjectural) identities for $\pi^2$: $$\sum_{k=1}^\infty\frac{145k^2-104k+18}{k^3(2k-1)\binom{2k}k\binom{3k}k^2}=\frac{\pi^2}3,\tag{1}$$ $$\sum_{k=1}^\infty\frac{...
Zhi-Wei Sun's user avatar
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10 votes
0 answers
509 views

New series for $\zeta(5)$ involving second-order harmonic numbers

In 1997 T. Amdeberhan and D. Zeilberger proved that $$\sum_{k=1}^\infty\frac{(-1)^k(205k^2-160k+32)}{k^5\binom{2k}k^5}=-2\zeta(3).\tag{1}$$ In 2008 J. Guillera obtained that $$\sum_{k=1}^\infty\frac{(...
Zhi-Wei Sun's user avatar
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