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 A355207 #13 Jun 25 2022 07:36:40
%S A355207 1,2,2,-6,-10,142,-434,-4478,88122,-688518,-4032346,268040678,
%T A355207 -5689167298,53999999466,1413830543394,-98561802143670,
%U A355207 3282601333608550,-59117973090349066,-1121454296035526786,171971593399059103618,-10034063428244586340158
%N A355207 E.g.f. A(x) satisfies A'(x) = 1 + 2 * A(1 - exp(-x)).
%H A355207 Seiichi Manyama, <a href="/A355207/b355207.txt">Table of n, a(n) for n = 1..329</a>
%F A355207 a(1) = 1; a(n+1) = 2 * Sum_{k=1..n} (-1)^(n-k) * Stirling2(n,k) * a(k).
%o A355207 (PARI) a_vector(n) = my(v=vector(n)); v[1]=1; for(i=1, n-1, v[i+1]=2*sum(j=1, i, (-1)^(i-j)*stirling(i, j, 2)*v[j])); v;
%Y A355207 Cf. A355093, A355203.
%K A355207 sign
%O A355207 1,2
%A A355207 _Seiichi Manyama_, Jun 24 2022