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 A355103 #9 Jun 19 2022 08:40:50
%S A355103 1,3,18,135,1008,4815,-38826,-1199646,-563904,519188373,3420802620,
%T A355103 -474196640841,-4490175699792,845516022777504,3767994187790868,
%U A355103 -2565470448416339190,31376572722070203168,11396618210613478642335,-523335368250939507824250
%N A355103 E.g.f. A(x) satisfies A(x) = 1 + 3 * x * A(1 - exp(-x)).
%F A355103 a(0) = 1; a(n) = 3 * n * Sum_{k=0..n-1} (-1)^(n-k-1) * Stirling2(n-1,k) * a(k).
%F A355103 a(n) = 3 * n * A355094(n-1) for n>0.
%o A355103 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=3*i*sum(j=0, i-1, (-1)^(i-j-1)*stirling(i-1, j, 2)*v[j+1])); v;
%Y A355103 Cf. A354574, A355102.
%Y A355103 Cf. A355094.
%K A355103 sign
%O A355103 0,2
%A A355103 _Seiichi Manyama_, Jun 19 2022