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 A009263 #17 Jun 25 2014 03:49:17
%S A009263 0,1,2,3,-4,-35,-18,679,2200,-18567,-150150,587499,11618004,-9780459,
%T A009263 -1078005082,-2502478065,118928710576,742659420913,-15184771406478,
%U A009263 -178572619407021,2148536703814700,44455465546363725
%N A009263 Expansion of e.g.f.: exp(tanh(x)).x.
%H A009263 Vincenzo Librandi, <a href="/A009263/b009263.txt">Table of n, a(n) for n = 0..100</a>
%F A009263 a(n) = n * A003723(n-1). - _Ralf Stephan_, Sep 01 2003
%t A009263 With[{nn=30},CoefficientList[Series[Exp[Tanh[x]]*x,{x,0,nn}],x] Range[ 0,nn]!] (* _Harvey P. Dale_, Jun 24 2014 *)
%K A009263 sign,easy
%O A009263 0,3
%A A009263 _R. H. Hardin_
%E A009263 Extended with signs by _Olivier Gérard_, Mar 15 1997
%E A009263 Definition clarified and prior Mathematica program replaced by _Harvey P. Dale_, Jun 24 2014