sum of a binomial coefficient
134361
Calculating the sum of a binomial coefficient series
57549
Finding the sum $\sum_{k=1}^rk^2\binom {n-k}{r-k}$
37771
Sum of a power series $n x^n$
51008
Evaluating a sum involving binomial coefficient in denominator
132249
Sum of every $k$th binomial coefficient.
70248
Closed-form expression for $\sum_{k=0}^n\binom{n}kk^p$ for integers $n,\,p$
47052
How can I simplify this expression involving binomial coefficients?
39957
Product of binomial coefficient as a basis
122891
integer as sum of three binomials
142303
Alternating sum of binomial coefficients multiplied by (1/k+1)
13236
Proving equality - a sum including binomial coefficient $\sum_{k=1}^{n}k{n \choose k}2^{n-k}=n3^{n-1}$
94189
Calculate the limit including binomial coefficients
19868
Evaluate: $ \sum _ {k=1}^{n}{\frac{k}{n}\binom{n}{k}t^k(1-t)^{n-k}}$
93617
Sum of the product of two combinations
45672
Even/Odd Binomial Coefficients
74294
How to simplify $\sum_{i=1}^{k}\binom{n + i - 1}{i}$?
279
Sum of two independent binomial variables