I have a algorithm and from the post its time complexity is: $\sum_{k=1}^{n}k\binom nk= n 2^{n-1}$
1158
How to prove this binomial identity $\sum_{r=0}^n {r {n \choose r}} = n2^{n-1}$?
54442
Sum of $k {n \choose k}$ is $n2^{n-1}$
5332
Find the value of $\sum_0^n \binom{n}{k} (-1)^k \frac{1}{k+1}$
135238
Time complexity function in terms of theta notation
30639
Efficient computation of $\sum_{k=1}^n \left\lfloor \frac{n}{k}\right\rfloor$
103347
combinatorial proof of summation
133905
Intuitive proof of $\sum_{k=1}^{n} \binom{n}{k} k^{k-1} (n-k)^{n-k} = n^n$
57549
Finding the sum $\sum_{k=1}^rk^2\binom {n-k}{r-k}$
70248
Closed-form expression for $\sum_{k=0}^n\binom{n}kk^p$ for integers $n,\,p$
14399
Calculate $\sum_{k=1}^n (-1)^{k+1} \binom{n}{k}\frac{1}{k}$
143047
find $\sum_{k=0}^{t}(-1)^k\binom{t}{k}^2$ for odd t then for even t
98082
Another combinatorics problem: $\sum\limits_{k = 0}^n (-1)^k \binom{2n-k}k2^{2n-2k}=2n+1$
136580
Proving $\sum_{k=0}^n\binom{2n}{2k} = 2^{2n-1}$
21000
Calculating $\sum_{k=1}^nk(k!)$ combinatorially
65983
Combinatorial proof of binomial coefficient summation identity
91933
Evaluate $\sum_{k=1}^nk\cdot k!$
116491
Closed form for $\sum_{k=0}^{m} {\binom {m}{k}} a^{k} (b+ck)^N$