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 A375868 #12 Sep 01 2024 09:34:58
%S A375868 1,2,14,178,3342,83594,2620998,98968034,4375295390,221781470202,
%T A375868 12684194298998,808136496137810,56767509202678094,4359070656483638762,
%U A375868 363283064756899367462,32658326649544884611010,3150270056733608259143422,324571774149991316277596378
%N A375868 E.g.f. satisfies A(x) = exp( 2 * (exp(x*A(x)) - 1) ).
%F A375868 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A349598.
%F A375868 a(n) = 2 * Sum_{k=0..n} (2*n+2)^(k-1) * Stirling2(n,k).
%o A375868 (PARI) a(n) = 2*sum(k=0, n, (2*n+2)^(k-1)*stirling(n, k, 2));
%Y A375868 Cf. A349598, A375869.
%Y A375868 Cf. A001861, A370054.
%K A375868 nonn
%O A375868 0,2
%A A375868 _Seiichi Manyama_, Sep 01 2024