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 A360032 #19 Feb 19 2023 09:21:09
%S A360032 1,1,4,27,257,3189,48843,889079,18730597,447945714,11983618199,
%T A360032 354519428597,11490618543066,404910044246256,15412461332440829,
%U A360032 630199633730994675,27548323149955792880,1282044807268698303751,63284535745130267484867
%N A360032 Expansion of Sum_{k>=0} (k * x * (1 + (k * x)^3))^k.
%F A360032 a(n) = Sum_{k=0..floor(n/4)} (n-3*k)^n * binomial(n-3*k,k).
%o A360032 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k*x*(1+(k*x)^3))^k))
%o A360032 (PARI) a(n) = sum(k=0, n\4, (n-3*k)^n*binomial(n-3*k, k));
%Y A360032 Cf. A360018, A360618.
%Y A360032 Cf. A360731.
%K A360032 nonn
%O A360032 0,3
%A A360032 _Seiichi Manyama_, Feb 19 2023