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 A009271 #14 Apr 01 2017 13:37:20
%S A009271 1,2,8,62,968,9962,557108,-202018,851334128,16341130322,
%T A009271 -6757456189972,2480221403307782,-678177401929552792,
%U A009271 194099813539570880762,-58073452241962644117532,18437894946039087568249262
%N A009271 Expansion of exp(tanh(x)*sinh(x)).
%t A009271 With[{nn=30},Take[CoefficientList[Series[Exp[Tanh[x]Sinh[x]],{x,0,nn}], x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Mar 16 2013 *)
%K A009271 sign
%O A009271 0,2
%A A009271 _R. H. Hardin_
%E A009271 Extended with signs by _Olivier Gérard_, Mar 15 1997