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0 votes
1 answer
277 views

Number of possible combinations of X numbers that sum to Y where the order doesn't matters

I am looking for the number of possible outcomes given to a set of numbers X that sum to Y. This is the same issue as here. However, I would like to consider that (i) the numbers can't be repeated and ...
Andrés Tello Urrea's user avatar
0 votes
1 answer
307 views

Get combination of numbers that when added same as the given number

For a given number $n >0$ is there a way to get combination that add up to this number?? for example : if $n=6$ then numbers that add up are $5+1,4+2,3+2+1$ so the combination is 3 if $n=4$ then ...
Akash Jain's user avatar
2 votes
0 answers
63 views

Closed-form solution of sum over compositions?

I am interested in calculating a closed-form solution of the following sum over compositions $$ \sum_{\substack{n_1 + \dots + n_M = N \\ n_i \geq 1}} \dfrac{n_1^2 + \dots + n_M^2}{n_1(N-n_1)! \dots ...
Ernesto Berríos-Caro's user avatar