Computing $\sum_{i=1}^k{i\cdot c^i}$
562
Formula for calculating $\sum_{n=0}^{m}nr^n$
107071
Prove $\sum_{k= 0}^{n} k \binom{n}{k} = n \cdot 2^{n - 1}$ using the binomial theorem
101017
What is the sum of $\sum\limits_{i=1}^{n}ip^i$?
155479
Summation of inner products
101138
Convergent or divergent: $\sum_{k=1}^{\infty}\frac{2^{k}\cdot k!}{k^{k}}$
126105
Compute $\sum_{k=1}^{n} \frac 1 {k(k + 1)} $
98808
Finite Sum $\sum_{i=1}^n\frac i {2^i}$
12812
Sum of the alternating harmonic series $\sum_{k=1}^{\infty}\frac{(-1)^{k+1}}{k} = \frac{1}{1} - \frac{1}{2} + \cdots $
25967
Prove $\csc(x)=\sum_{k=-\infty}^{\infty}\frac{(-1)^k}{x+k\pi}$
36361
How to calculate the summation $(\sum_{p = k}^{n} \binom{n}{p}) / 2^n$ quickly?
155769
Prove $\sum_{k= 0}^{n} k \binom{n}{k} = n \cdot 2^{n-1}$ using the binomial theorem for $n\geq1$
63064
How to compute sum of sum (linear analysis)
78309
On an expansion of $(1+a+a^2+\cdots+a^n)^2$
30724
Summation splitting: $\sum_{n=1}^{\infty} \frac{n}{3\cdot 5\cdot 7 \dots (2n+1)}$
124135
A general formula for $\sum (k-1)(k-2)(k-3)$?
127150
Finding general formula of $\sum_{i=0}^n i^2 \binom{n}{i}$
37007
Evaluating $\sum_{k=1}^{n} \frac{1}{k(k+1)}$