query: What is the sum $\sum_{n=1}^\infty \frac 1{2^n} \tan \frac 1{2^{n+1}}$?
positive_passages.docid: 17438
positive_passages.text: Evaluate $\lim_{n\to \infty} \sum_{r=1}^n \frac {1}{2^r}\tan \left(\frac {1}{2^r}\right)$
negative_passages.docid: 14223
negative_passages.text: Find the infinite sum $\sum_{n=1}^{\infty}\frac{1}{2^n-1}$
negative_passages.docid: 89771
negative_passages.text: $\frac{1}{s-1}+\sum_{n=1}^{\infty}\left[\frac{1}{n^s}+\frac{1}{s-1}\left(\frac{1}{(n+1)^{s-1}} - \frac{1}{n^{s-1}}\right)\right]$
negative_passages.docid: 28378
negative_passages.text: Find the infinite sum of the series $\sum_{n=1}^\infty \frac{1}{n^2 +1}$
negative_passages.docid: 28254
negative_passages.text: Why $\sum_{k=1}^{\infty} \frac{k}{2^k} = 2$?
negative_passages.docid: 29170
negative_passages.text: Find the sum of the series $\sum \frac{1}{n(n+1)(n+2)}$
negative_passages.docid: 130548
negative_passages.text: What is the sum of the power series: $\sum_{k=2}^\infty\frac{x^k}{k(k-1)}$?
negative_passages.docid: 32637
negative_passages.text: What is the sum of this series: $\displaystyle\sum_{n=0}^{\infty} \dfrac{a^n}{(3n)!}$
negative_passages.docid: 52278
negative_passages.text: How to solve $\sum_{k=2}^\infty {\frac{1}{k^2-1}}$
negative_passages.docid: 53658
negative_passages.text: Find the sum series $\sum_{n=1}^{+\infty} \frac{(-1)^{n-1}(2n-1)}{2^{n-1}}$
negative_passages.docid: 7177
negative_passages.text: Find sum of series $ \sum_{n=1}^{\infty} (n\cdot \ln \frac{2n+1}{2n-1} - 1) $
negative_passages.docid: 43903
negative_passages.text: Find the sum for $\sum_{n=1}^{\infty}(-1)^{(n+1)}\frac{2n+1}{3^n} $
negative_passages.docid: 116723
negative_passages.text: Evaluating the sum $\sum_{n=1}^{\infty}\dfrac{(-1)^{n}}{n^{2}}$
negative_passages.docid: 47706
negative_passages.text: Find the value of $ \sum_{n=1}^{\infty} \frac{n^3}{3^n} $
negative_passages.docid: 104078
negative_passages.text: Calculate the sum of the infinite series $\sum_{n=0}^{\infty} \frac{n}{4^n}$
negative_passages.docid: 137249
negative_passages.text: find $\sum_{k=2}^{\infty}\frac{1}{k^2-1}$
negative_passages.docid: 150148
negative_passages.text: Sum of $\sum^\infty_{n=2} \frac{1}{\ln{(n!)}}$