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 A009274 #15 Aug 25 2012 14:29:19
%S A009274 1,1,1,2,5,32,157,688,3817,29952,257049,1922560,15886125,160364544,
%T A009274 1844058101,19815696384,218349214545,2743045259264,38729647296945,
%U A009274 538516252917760,7468216325125589,112957538226929664,1882371895493492429
%N A009274 E.g.f.: exp(tanh(x)/cos(x)).
%t A009274 With[{nn=30},CoefficientList[Series[Exp[Tanh[x]/Cos[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Aug 25 2012 *)
%o A009274 (PARI) for(n=1,#t=Vec(exp(tanh(x)/cos(x))),print1((n-1)!*t[n]",")) \\ - _M. F. Hasler_, Aug 25 2012
%K A009274 nonn
%O A009274 0,4
%A A009274 _R. H. Hardin_
%E A009274 Extended and formatted by _Olivier Gérard_, Mar 15 1997
%E A009274 Definition clarified by _Harvey P. Dale_, Aug 25 2012