Posted by haifeng on 2013-07-25 10:01:17 last update 2019-12-17 19:00:12 | Answers (0) | 收藏
Jakob Bernoulli 证明了
\[ \sum_{k=1}^{\infty}\frac{k^2}{2^k}=6,\quad\sum_{k=1}^{\infty}\frac{k^3}{2^k}=26. \]
James A. Sellers, The infinite series of Euler and the Bernoulli's spice up a calculus class