The series $1-1+1-1+\dots$
115816
Grandi's Series; tends to $1/2$, but why is this considered a valid sum?
29170
Find the sum of the series $\sum \frac{1}{n(n+1)(n+2)}$
42216
Sum of infinite series $\sum_{i=1}^{\infty} \frac 1 {i(i+1)(i+2)...(i+n)}$
58286
Why does the $\sum_{n>1}(\zeta(n)-1)=1?$
128608
Closed form for the series $a+a^p+(a^p)^p+\dots$
122445
Sum of the series:$\frac{1}{1\cdot 2}+\frac{1\cdot3}{1\cdot2\cdot3\cdot4}+\cdots$
125933
On the series $\sum \limits_{n=2}^{\infty} \frac{(-1)^n}{n \log n}$
145322
Sum of a Hyper-geometric series. (NBHM 2011)
136459
Prove ${n - 1 \choose k - 1} + {n - 2 \choose k - 1} + {n - 3 \choose k - 1} + \dots + {k - 1 \choose k - 1} = {n \choose k}$
44649
Summing a series having a geometric component
55061
Evaluating the sum after reordering an infinite series $1-\frac {1} {2}+\frac {1} {3}-\frac {1} {4}+\ldots $
134633
How to sum this series for $\pi/2$ directly?
30724
Summation splitting: $\sum_{n=1}^{\infty} \frac{n}{3\cdot 5\cdot 7 \dots (2n+1)}$
94943
Sum of series with addition: $\sum_{n=1}^\infty \frac{1}{n^2(n+1)}$
8666
Let us define a series $\{a(n)\}$ such that $a(n)= a(n-1) + \frac{1}{a(n-1)}$
120988
Infinite Series $\sum 1/(n(n+1))$
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 $