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 A368536 #10 Dec 29 2023 08:06:40
%S A368536 0,1,14,192,2996,53955,1110786,25808160,668740808,19129643325,
%T A368536 598902606310,20371538593296,748148581865532,29505258575474591,
%U A368536 1243695052515891626,55800352470853933440,2655106829377875895056,133547801741230053460761
%N A368536 a(n) = Sum_{k=1..n} binomial(k+1,2) * n^k.
%F A368536 a(n) = [x^n] n*x/((1-x) * (1-n*x)^3).
%F A368536 a(n) = n * (n^n * (n^4-n^3-3*n^2+3*n+2) - 2)/(2 * (n-1)^3) for n > 1.
%o A368536 (PARI) a(n) = sum(k=1, n, binomial(k+1, 2)*n^k);
%Y A368536 Cf. A062806, A368537.
%Y A368536 Cf. A368526.
%K A368536 nonn,easy
%O A368536 0,3
%A A368536 _Seiichi Manyama_, Dec 29 2023