How do I sum 1/6( e^t + e^2t + .... + e^6t)?
58633
Proof of the formula $1+x+x^2+x^3+ \cdots +x^n =\frac{x^{n+1}-1}{x-1}$
18975
How to 'sum' a standard deviation?
41840
How do I evaluate this sum(involving the floor function)?
4253
How to calculate: $\sum_{n=1}^{\infty} n a^n$
1379
Summation of $n^2x^n$ terms
100896
What is the sum of this? $ 1 + \frac12 + \frac13 + \frac14 + \frac16 + \frac18 + \frac19 + \frac1{12} +\cdots$
108461
Sum of Harmonic Numbers
8905
Sum the series $\frac{3}{1⋅2⋅4}+\frac{4}{2⋅3⋅5}+ \frac{5}{3⋅4⋅6}+...\text{(upto n terms)}$
26446
Find the sum : $\displaystyle\sum_{i=0}^n \frac{2^i}{1+x^{2^{i}}}$
113189
Find the sum of the series $1^2-2^2+3^2-4^2+...-(2n)^2$
36361
How to calculate the summation $(\sum_{p = k}^{n} \binom{n}{p}) / 2^n$ quickly?
78632
Summation equation for $2^{x-1}$
146274
Fastest way to do this double summation?
52278
How to solve $\sum_{k=2}^\infty {\frac{1}{k^2-1}}$
77517
Why is this sum a representation of e?
18814
Sum of the series $1+\frac{1\cdot 3}{6}+\frac{1\cdot3\cdot5}{6\cdot8}+\cdots$
93690
How to obtain the sum of the following series? $\sum_{n=1}^\infty{\frac{n^2}{2^n}}$