Sum of $1^2 + 2^2 + ... +n^2$
16472
Sum of First $n$ Squares Equals $\frac{n(n+1)(2n+1)}{6}$
94943
Sum of series with addition: $\sum_{n=1}^\infty \frac{1}{n^2(n+1)}$
84147
Evaluating $\sum_{n=1}^\infty \frac{2^{2n-1}}{5^{n+1}}$
151477
computing the series $\sum_{n=1}^\infty \frac{1}{n^2 2^n}$
153409
Sum of $1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{6}+\frac{1}{8}+\frac{1}{9}+\frac{1}{12}+\cdots$
127806
How to find the sum of the series $\sum_{k=2}^\infty \frac{1}{k^2-1}$?
44928
Show $\sum_n \frac{z^{2^n}}{1-z^{2^{n+1}}} = \frac{z}{1-z}$
50050
A formula for the power sums: $1^n+2^n+\dotsc +k^n=\,$?
64581
How to find the sum $\sum\limits_{k=1}^n (k^2+k+1)k!$?
30518
Formula for $\sum_{k=1}^n \frac{1}{k(k+1)(k+2)}$?
55339
Find the sum $\sum_{n=1}^{\infty}\frac{ 1}{n^{2}(2n-1)}$
75457
How do i simplify the following: $\sum_{i=1}^n (3i^2+4) - \sum_{j=2}^{n+1} (3j^2+1)$
29170
Find the sum of the series $\sum \frac{1}{n(n+1)(n+2)}$
67752
Show that $\sum_{n = 1}^{+\infty} \frac{n}{2^n} = 2$
139074
Question about $a_n=\sum_{k=1}^n \frac{n}{n^2+k}\ $for $ n \in\mathbb{N}$
57549
Finding the sum $\sum_{k=1}^rk^2\binom {n-k}{r-k}$
127189
sum of this series: $\sum_{n=1}^{\infty}\frac{1}{4n^2-1}$