What's the sum of this series?
158737
What is the value of the series $\sum\limits_{n=1}^\infty \frac{(-1)^n}{n^2}$?
7177
Find sum of series $ \sum_{n=1}^{\infty} (n\cdot \ln \frac{2n+1}{2n-1} - 1) $
62271
Find the sum of the series: $\cos^3 \alpha +\cos^3 {3\alpha} + \cos^3 {5\alpha}+....+\cos^3 {(2n-1)\alpha}$.
91458
Sum of the series $\binom{n}{0}-\binom{n-1}{1}+\binom{n-2}{2}-\binom{n-3}{3}+..........$
32637
What is the sum of this series: $\displaystyle\sum_{n=0}^{\infty} \dfrac{a^n}{(3n)!}$
83641
The sum of the series $\frac{15}{16}+\frac{15}{16} \times \frac{21}{24}+\frac{15}{16} \times \frac{21}{24} \times \frac{27}{32}+\dots$
91410
Finding the sum of this series: $1+\frac 12 + \frac 13 + \cdots + \frac 1{50}$
117843
Finding the sum of series $\sum_{n=0}^∞ \frac{2^n + 3^n}{6^n}$
35036
Series $\sum_{n=1}^{\infty}\frac{\cos(nx)}{n^2}$
94943
Sum of series with addition: $\sum_{n=1}^\infty \frac{1}{n^2(n+1)}$
104078
Calculate the sum of the infinite series $\sum_{n=0}^{\infty} \frac{n}{4^n}$
112036
sum of series $\frac{n}{1\cdot 2 \cdot 3}+\frac{n-1}{2\cdot 3\cdot 4}+\frac{n-2}{3\cdot 4 \cdot 5}+\cdots \cdots n$ terms
123951
Problem calculating sum of convergent series of $\sum_{n=2}^{\infty} \frac{1}{n^{2}-1}$
113189
Find the sum of the series $1^2-2^2+3^2-4^2+...-(2n)^2$
49028
Find the sum : $\frac{1}{\cos0^\circ\cos1^\circ}+\frac{1}{\cos1^\circ \cos2^\circ} +\frac{1}{\cos2^\circ \cos3^\circ}+......+$
51146
Sum of Infinite Series $1 + 1/2 + 1/4 + 1/16 + \cdots$
113713
Closed formula for the sum of the following series