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 A370085 #9 Feb 09 2024 01:48:40
%S A370085 1,1,21,3421,2232361,4047831801,16492042429501,131524059703672021,
%T A370085 1862832637043775536721,43582296764832433769579761,
%U A370085 1592318494850388661944336320101,86870590496672779178378519636679501,6822481321458299127004125050236325798521
%N A370085 Expansion of e.g.f. exp( Sum_{k>=1} (3*k)! * (x/6)^k/k ).
%F A370085 a(0) = 1; a(n) = (n-1)! * Sum_{k=1..n} (3*k)! * a(n-k) / (6^k * (n-k)!).
%o A370085 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(sum(k=1, N, (3*k)!*(x/6)^k/k))))
%Y A370085 Cf. A158876, A370084.
%Y A370085 Cf. A370087.
%K A370085 nonn
%O A370085 0,3
%A A370085 _Seiichi Manyama_, Feb 08 2024