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 A371045 #8 Mar 09 2024 08:16:30
%S A371045 1,0,0,6,24,60,840,15330,161616,1572984,29031120,636008670,
%T A371045 11426850600,210095235636,5137568918664,139255673359530,
%U A371045 3574532174656800,95923063388359920,2974073508961556256,98747639807081454774,3287535337205171488440
%N A371045 E.g.f. satisfies A(x) = 1 + x^3*A(x)*exp(x*A(x)).
%F A371045 a(n) = n! * Sum_{k=0..floor(n/3)} k^(n-3*k) * binomial(n-2*k+1,k)/( (n-2*k+1)*(n-3*k)! ).
%o A371045 (PARI) a(n) = n!*sum(k=0, n\3, k^(n-3*k)*binomial(n-2*k+1, k)/((n-2*k+1)*(n-3*k)!));
%Y A371045 Cf. A370985, A371019, A371044, A371046.
%Y A371045 Cf. A365285.
%K A371045 nonn
%O A371045 0,4
%A A371045 _Seiichi Manyama_, Mar 09 2024