find-S-n-k-0-n-k-2-C-n-k-2-

Question Number 66798 by mathmax by abdo last updated on 19/Aug/19

$${find}\:{S}_{{n}} =\sum_{{k}=\mathrm{0}} ^{{n}} \:{k}^{\mathrm{2}} \:\left({C}_{{n}} ^{{k}} \right)^{\mathrm{2}} \\ $$