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 A009244 #17 May 25 2022 01:50:23
%S A009244 1,1,2,6,20,92,448,2688,17296,127312,1013600,8850336,83547584,
%T A009244 845380928,9196867072,105911556096,1301697829120,16814357324032,
%U A009244 230093807905280,3294279618252288,49636887216382976
%N A009244 Expansion of e.g.f.: exp(tan(x))/cos(x).
%H A009244 Vaclav Kotesovec, <a href="/A009244/b009244.txt">Table of n, a(n) for n = 0..477</a>
%H A009244 P. Barry, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL17/Barry2/barry281.html">Constructing Exponential Riordan Arrays from Their A and Z Sequences</a>, Journal of Integer Sequences, 17 (2014), #14.2.6.
%t A009244 With[{nn=30},CoefficientList[Series[Exp[Tan[x]]/Cos[x],{x,0,nn}],x] Range[ 0,nn]!] (* _Harvey P. Dale_, Jun 06 2014 *)
%K A009244 nonn,easy
%O A009244 0,3
%A A009244 _R. H. Hardin_
%E A009244 Extended and signs tested by _Olivier Gérard_, Mar 15 1997
%E A009244 Prior Mathematica program replaced and definition clarified by _Harvey P. Dale_, Jun 06 2014