This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A383136 #9 Apr 17 2025 12:27:58
%S A383136 0,1,8,45,216,945,3888,15309,58320,216513,787320,2814669,9920232,
%T A383136 34543665,119042784,406552365,1377495072,4634696961,15496819560,
%U A383136 51526925037,170465015160,561372288561,1841022163728,6014703091725,19581781196016,63546645708225,205608702558168
%N A383136 a(n) = Sum_{k=0..n} k^2 * 2^(n-k) * binomial(n,k).
%F A383136 a(n) = 3^(n-2) * n * (2 + n).
%o A383136 (PARI) a(n) = 3^(n-2)*n*(2+n);
%Y A383136 Cf. A027471, A383137, A383138, A383139.
%K A383136 nonn,easy
%O A383136 0,3
%A A383136 _Seiichi Manyama_, Apr 17 2025