$\sum_{n=1}^{\infty} {\frac{1}{4^n \cos^2 (\frac{\pi}{2^{n+2}})}}$
44754
Infinite Series $\sum\limits_{n=1}^{\infty}\frac{1}{4^n\cos^2\frac{x}{2^n}}$
14223
Find the infinite sum $\sum_{n=1}^{\infty}\frac{1}{2^n-1}$
92754
Closed form for the series: $\sum_{n=1}^{\infty}x^{n^2}$
42742
Is $\sum_{n=1}^\infty \frac{\sin(2n)}{1+\cos^4(n)}$ convergent?
137027
Find the value of $\sum_{n=0}^\infty\frac{1}{9n^2+9n+2}$
132613
Testing the series $\sum\limits_{n=1}^{\infty} \frac{1}{n^{k + \cos{n}}}$
141390
Closed form for $\sum_{n=-\infty}^\infty \frac{1}{(z+n)^2+a^2}$
81589
Find the sum of $\sum_{k=0}^{\infty} 1/[(r+2k+2)(s+2k+2)]$
121617
Closed form of $\sum_{n=0}^{\infty} \frac{\cos(\alpha \, n)}{n!}$
29170
Find the sum of the series $\sum \frac{1}{n(n+1)(n+2)}$
121337
Divergence of $\sum_{n=1}^{\infty} \frac{1}{2+i^n}$?
151477
computing the series $\sum_{n=1}^\infty \frac{1}{n^2 2^n}$
117056
How to show $\sum_{n=1}^{\infty}\frac{H_{n+1}}{n(n+1)}=2$?
24373
Hint on computing the series $\sum_{n=2}^\infty \frac{1}{n^2-1}$.
142985
Finding sum of series $\sum^{\infty}_{k=0}\frac{(k+1)(k+2)}{2^k}$
114031
Show that $\sum_{n=0}^\infty r^n e^{i n \theta} = \frac{1- r\cos(\theta)+i r \sin(\theta)}{1+r^2-2r\cos(\theta)}$
28378
Find the infinite sum of the series $\sum_{n=1}^\infty \frac{1}{n^2 +1}$