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 A353779 #12 May 10 2022 14:26:24
%S A353779 1,0,-2,8,-24,144,-720,7552,-35840,427520,-3628800,45415424,
%T A353779 -479001600,7094226944,-82614884352,1741160087552,-20922789888000,
%U A353779 371094631612416,-6402373705728000,137529198176370688,-2379913632645120000,55730621780175355904
%N A353779 Product_{n>=1} (1 + a(n)*x^n/n!) = 1 + tanh(x).
%t A353779 nn = 22; f[x_] := Product[(1 + a[n] x^n/n!), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - 1 - Tanh[x], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten
%Y A353779 Cf. A006973, A137852, A155585, A353607, A353608, A353609, A353610, A353611.
%K A353779 sign
%O A353779 1,3
%A A353779 _Ilya Gutkovskiy_, May 08 2022