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 A009248 #10 Jun 11 2014 14:30:37
%S A009248 1,1,3,12,57,332,2209,16730,140609,1302664,13137441,143354574,
%T A009248 1680017889,21043179068,280310970385,3955899181730,58931602709633,
%U A009248 923925812276752,15201851967182913,261859798838325270
%N A009248 Expansion of e.g.f.: exp(tan(x).exp(x)).
%t A009248 With[{nn=20},CoefficientList[Series[Exp[Tan[x]*Exp[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Jun 11 2014 *)
%K A009248 nonn,easy
%O A009248 0,3
%A A009248 _R. H. Hardin_
%E A009248 Extended and signs tested Mar 15 1997 by _Olivier Gérard_.
%E A009248 Previous Mathematica program replaced and definition clarified by _Harvey P. Dale_, Jun 11 2014