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 A365977 #10 Sep 24 2023 09:16:23
%S A365977 1,1,2,6,24,120,840,6720,60480,604800,6652800,83462400,1138233600,
%T A365977 16746912000,264176640000,4444771968000,80719172352000,
%U A365977 1556132497920000,31722198842880000,681437830993920000,15378172899747840000,366025806545817600000
%N A365977 Expansion of e.g.f. 1 / ( 1 - Sum_{k>=0} x^(5*k+1) / (5*k+1) ).
%F A365977 a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/5)} (5*k)! * binomial(n,5*k+1) * a(n-5*k-1).
%o A365977 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=0, N\5, x^(5*k+1)/(5*k+1)))))
%Y A365977 Cf. A296676, A365975, A365976.
%Y A365977 Cf. A365969.
%K A365977 nonn
%O A365977 0,3
%A A365977 _Seiichi Manyama_, Sep 23 2023