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 A365978 #9 Sep 24 2023 09:16:27
%S A365978 1,0,1,0,6,24,90,1008,7560,54432,712152,7620480,81130896,1266632640,
%T A365978 17587441872,246734377344,4527397929600,77238618702336,
%U A365978 1340945212763520,28407941067018240,574640938744314624,11868502219930137600,285787326567523173120
%N A365978 Expansion of e.g.f. 1 / ( 1 - Sum_{k>=0} x^(3*k+2) / (3*k+2) ).
%F A365978 a(0) = 1; a(n) = Sum_{k=0..floor((n-2)/3)} (3*k+1)! * binomial(n,3*k+2) * a(n-3*k-2).
%o A365978 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=0, N\3, x^(3*k+2)/(3*k+2)))))
%Y A365978 Cf. A226226, A365979.
%Y A365978 Cf. A365908.
%K A365978 nonn
%O A365978 0,5
%A A365978 _Seiichi Manyama_, Sep 23 2023