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 A368292 #6 Dec 20 2023 12:37:05
%S A368292 1,2,11,97,1109,15821,271255,5425967,124032137,3189663433,91141189931,
%T A368292 2864686414547,98226339773677,3648723468367277,145961603607355775,
%U A368292 6256040115149251591,286015221831125756945,13893373399551594686609,714578347872583574806099
%N A368292 Expansion of e.g.f. exp(x) / (1 - x*exp(3*x)).
%F A368292 a(n) = n! * Sum_{k=0..n} (3*(n-k)+1)^k / k!.
%o A368292 (PARI) a(n) = n!*sum(k=0, n, (3*(n-k)+1)^k/k!);
%Y A368292 Cf. A336948, A368293.
%K A368292 nonn,easy
%O A368292 0,2
%A A368292 _Seiichi Manyama_, Dec 19 2023