Solve this combination with a summation. Edited and maybe Solved
36786
Prove $\sum\limits_{i=0}^n\binom{i+k-1}{k-1}=\binom{n+k}{k}$ (a.k.a. Hockey-Stick Identity)
115433
Find the summation of given expression: $\sum_{k=1}^n k^3\binom nk$
128774
Unexpected result of summation
8806
Summation of binomial coefficients
69045
Solving this summation: $\sum_{i=1}^k i\cdot2^i$
31731
How to turn this into an equation and then sum the series?
140458
Infinite summation involving exponents
109461
Solving equation involving Euler's totient function
114270
How do I solve this equation?
81589
Find the sum of $\sum_{k=0}^{\infty} 1/[(r+2k+2)(s+2k+2)]$
141978
How to find the infinite sum
155496
sum of combinations $\binom n{0} + \binom n{3} + \binom n{6} +... +\binom n{3k}$
93094
How do I solve this problem on maximizing sum modulo a given number?
27637
How can I apply Newton's sums to solve this problem?
112827
Find the sum of the binomial coefficients
114889
Solve summation $\sum_{i=1}^n \lfloor e\cdot i \rfloor $
38037
A problem with my reasoning in a problem about combinations