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 A351905 #15 Feb 25 2022 12:11:08
%S A351905 1,1,1,1,-23,-119,-359,-839,18481,178417,902161,3318481,-69866279,
%T A351905 -1011908039,-7204341143,-36194591159,726745175521,14326789219681,
%U A351905 131901636673441,840736509931297,-16060449291985079,-408041402342457239,-4618341644958693959,-35691963052019431079
%N A351905 Expansion of e.g.f. exp(x * (1 - x^3)).
%F A351905 a(n) = n! * Sum_{k=0..floor(n/4)} (-1)^k * binomial(n-3*k,k)/(n-3*k)!.
%F A351905 a(n) = a(n-1) - 4! * binomial(n-1,3) * a(n-4) for n > 3.
%o A351905 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(exp(x*(1-x^3))))
%o A351905 (PARI) a(n) = n!*sum(k=0, n\4, (-1)^k*binomial(n-3*k, k)/(n-3*k)!);
%o A351905 (PARI) a(n) = if(n<4, 1, a(n-1)-4!*binomial(n-1, 3)*a(n-4));
%Y A351905 Cf. A293604, A246607, A351906.
%Y A351905 Cf. A190875, A293493.
%K A351905 sign
%O A351905 0,5
%A A351905 _Seiichi Manyama_, Feb 25 2022