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 A009301 #16 Apr 01 2017 14:00:24
%S A009301 1,1,1,-2,-11,-4,181,624,-3863,-37808,66121,2529440,4478365,
%T A009301 -197245632,-1211701763,17275207936,226423491793,-1517532372736,
%U A009301 -43068302925551,78275049887232,8876725117679941,24598365340871680,-1997577117130009403,-16151599386896207872,483811389670392875449
%N A009301 E.g.f. exp(x/cosh(x)).
%t A009301 With[{nn=30},CoefficientList[Series[Exp[x/Cosh[x]],{x,0,nn}],x] Range[ 0,nn]!] (* _Harvey P. Dale_, Jan 26 2016 *)
%o A009301 (PARI)
%o A009301 N=33; x='x+O('x^N);
%o A009301 egf=exp(x*1/cosh(x));
%o A009301 Vec(serlaplace(egf))
%o A009301 /* _Joerg Arndt_, Sep 15 2012 */
%Y A009301 Cf. A009118, A009562.
%K A009301 sign,easy
%O A009301 0,4
%A A009301 _R. H. Hardin_
%E A009301 Extended with signs by _Olivier Gérard_, Mar 15 1997