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 A009420 #15 Jun 23 2015 21:41:39
%S A009420 0,1,1,2,-8,-11,-19,846,-1896,-111,-228159,2453010,-11353440,
%T A009420 173733429,-3565851587,41759789358,-501111404080,9579604130881,
%U A009420 -176443305192159,2870638703204994,-53275482352387864,1134671091039714069
%N A009420 Expansion of log(1+x)*exp(tanh(x)).
%F A009420 a(n) ~ (n-1)! * (-1)^(n+1) * exp(-tanh(1)). - _Vaclav Kotesovec_, Jan 23 2015
%t A009420 Log[ 1+x ]*Exp[ Tanh[ x ] ]
%t A009420 CoefficientList[Series[E^Tanh[x]*Log[1 + x], {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jan 23 2015 *)
%K A009420 sign,easy
%O A009420 0,4
%A A009420 _R. H. Hardin_
%E A009420 Extended with signs by _Olivier Gérard_, Mar 15 1997