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 A334855 #4 May 13 2020 19:00:19
%S A334855 1,2,7,32,141,-48,-20509,-572416,-13236455,-290711040,-6196120193,
%T A334855 -125279895552,-2200506714587,-21844509804544,731664799971163,
%U A334855 69257460487553024,3772508483052129329,174474102931077464064,7365599642083503837175,286164434343334028247040
%N A334855 E.g.f. A(x) satisfies: A(x) = tanh(x * exp(A(x))).
%F A334855 E.g.f.: series reversion of arctanh(x) / exp(x).
%t A334855 nmax = 20; CoefficientList[InverseSeries[Series[ArcTanh[x]/Exp[x], {x, 0, nmax}], x], x] Range[0, nmax]! // Rest
%Y A334855 Cf. A227463, A227465.
%K A334855 sign
%O A334855 1,2
%A A334855 _Ilya Gutkovskiy_, May 13 2020