Do you know any combinatorial proof of:
$$\sum\limits_{k=1}^n k^2 {n \choose k} = n(n+1)2^{n-2}$$?
2026-03-27 15:36:04.1774625764
Combinatorial proof of $\sum\limits_{k=1}^n k^2 {n \choose k} = n(n+1)2^{n-2}$
128 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail AtRelated Questions in COMBINATORICS
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