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 A377803 #14 Nov 08 2024 08:03:02
%S A377803 1,1,5,51,798,16914,453294,14704542,560274336,24529661568,
%T A377803 1213557885720,66956662956600,4076440417367856,271472012197547472,
%U A377803 19631093304600307152,1531919987372848152240,128314172533501646058240,11482569303348317402868480,1093343670892117401737893632
%N A377803 Expansion of e.g.f. (1/x) * Series_Reversion( x/(1 - log(1-3*x) / 3) ).
%H A377803 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A377803 a(n) = n! * Sum_{k=0..n} 3^(n-k) * |Stirling1(n,k)|/(n-k+1)!.
%o A377803 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(serreverse(x/(1-log(1-3*x)/3))/x))
%o A377803 (PARI) a(n) = n!*sum(k=0, n, 3^(n-k)*abs(stirling(n, k, 1))/(n-k+1)!);
%Y A377803 Cf. A138013, A377737.
%Y A377803 Cf. A352069, A370907, A370939, A377790.
%K A377803 nonn
%O A377803 0,3
%A A377803 _Seiichi Manyama_, Nov 08 2024