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 A357904 #9 Oct 19 2022 13:40:35
%S A357904 1,0,0,0,1,1,1,1,2,4,8,16,33,70,153,346,814,2000,5138,13776,38395,
%T A357904 110695,328638,1001306,3124626,9978906,32620854,109225582,374875483,
%U A357904 1319392590,4761630252,17610041358,66668257846,258018795970,1019440760020,4106982942054
%N A357904 a(n) = Sum_{k=0..floor(n/4)} Stirling2(n - 3*k,k).
%F A357904 G.f.: Sum_{k>=0} x^(4*k)/Product_{j=1..k} (1 - j * x).
%o A357904 (PARI) a(n) = sum(k=0, n\4, stirling(n-3*k, k, 2));
%o A357904 (PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=0, N, x^(4*k)/prod(j=1, k, 1-j*x)))
%Y A357904 Cf. A000110, A171367, A357903.
%K A357904 nonn
%O A357904 0,9
%A A357904 _Seiichi Manyama_, Oct 19 2022