Sum of a weird almost-geometric series: $\frac{1}{365}\sum_{x=1}^{\infty} x\left(\frac{364}{365}\right)^{x-1}$
6416
How can I evaluate $\sum_{n=0}^\infty(n+1)x^n$?
105151
Geometric Summation Question $\sum_{n=2}^{\infty} n(n-1)x^{(n-2)} = \frac{2}{(1-x)^3}$
127806
How to find the sum of the series $\sum_{k=2}^\infty \frac{1}{k^2-1}$?
82069
How to explain the formula for the sum of a geometric series without calculus?
64012
Limit of a geometric series
152227
How to sum this series to infinity: $\sum_{n=0}^{\infty} \frac1{2^{2^n}}$
64223
Infinite Series $\sum\limits_{n=1}^\infty\left(\frac{H_n}n\right)^2$
155611
Sum of series $\frac{1}{2 \cdot 3 \cdot 4} + \frac{1}{4 \cdot 5 \cdot 6} + \frac{1}{6 \cdot 7 \cdot 8} + \cdots $
104078
Calculate the sum of the infinite series $\sum_{n=0}^{\infty} \frac{n}{4^n}$
43320
Find the sum of the power series $\sum_{n=1}^\infty n*(n+1)*x^n$
49262
Evaluation of Sum of $ \sum_{n=1}^{\infty}\frac{\sin (n)}{n}$.
43903
Find the sum for $\sum_{n=1}^{\infty}(-1)^{(n+1)}\frac{2n+1}{3^n} $
55777
A tricky sum to infinity
108010
Evaluating $\sum_{k=1}^{\infty}\left(\frac{\sin(tk)}{k}\right)^2$
145322
Sum of a Hyper-geometric series. (NBHM 2011)
53658
Find the sum series $\sum_{n=1}^{+\infty} \frac{(-1)^{n-1}(2n-1)}{2^{n-1}}$
148940
$\sum_{n=1}^\infty\frac1{n^6}=\frac{\pi^6}{945}$ by Fourier series of $x^2$