How this infinite sum $\sum_1^\infty\frac{(-1)^{n-1}(2n-1)}{2^{n-1}}$ equals 2/9?
53658
Find the sum series $\sum_{n=1}^{+\infty} \frac{(-1)^{n-1}(2n-1)}{2^{n-1}}$
42216
Sum of infinite series $\sum_{i=1}^{\infty} \frac 1 {i(i+1)(i+2)...(i+n)}$
150563
Find the sum $\sum_{n=1}^{\infty} \frac{\ln n}{n(n- \ln n)}$
10460
Why does $\sum_{n = 0}^\infty \frac{n}{2^n}$ converge to 2?
104078
Calculate the sum of the infinite series $\sum_{n=0}^{\infty} \frac{n}{4^n}$
120988
Infinite Series $\sum 1/(n(n+1))$
89771
$\frac{1}{s-1}+\sum_{n=1}^{\infty}\left[\frac{1}{n^s}+\frac{1}{s-1}\left(\frac{1}{(n+1)^{s-1}} - \frac{1}{n^{s-1}}\right)\right]$
127806
How to find the sum of the series $\sum_{k=2}^\infty \frac{1}{k^2-1}$?
61850
Compute $\sum_{k=0}^{\infty}\frac{1}{2^{k!}}$
12480
Convergence of $\sum_{n=1}^{\infty} \frac{\frac{1}{2}+(-1)^n}{n}$
28378
Find the infinite sum of the series $\sum_{n=1}^\infty \frac{1}{n^2 +1}$
92690
Infinite Series $\sum\limits_{n=0}^{\infty}\arctan(\frac{1}{F_{2n+1}})$
24373
Hint on computing the series $\sum_{n=2}^\infty \frac{1}{n^2-1}$.
137027
Find the value of $\sum_{n=0}^\infty\frac{1}{9n^2+9n+2}$
138313
How to sum $\sum_{n=1}^{\infty} \frac{1}{n^2 + a^2}$?
58286
Why does the $\sum_{n>1}(\zeta(n)-1)=1?$
76387
Evaluate the series $\sum_{n=1}^{\infty} \frac{2^{[\sqrt{n}]}+2^{-[\sqrt{n}]}}{2^n}$