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 A024293 #18 Apr 02 2017 15:37:06
%S A024293 0,1,-10,256,-13840,1282816,-181649920,36478744576,-9861412096000,
%T A024293 3452931391553536,-1520176422094766080,821908023102140317696,
%U A024293 -535369559186849435484160,413508899951810581475885056,-373681769282729298809313034240,390605070751731814007608616943616
%N A024293 Expansion of e.g.f. log(1+sin(x)^2)/2 (even-indexed coefficients).
%t A024293 With[{nn=30},Take[CoefficientList[Series[Log[1+Sin[x]^2]/2,{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, May 21 2014 *)
%Y A024293 Cf. A009344.
%K A024293 sign
%O A024293 0,3
%A A024293 _R. H. Hardin_
%E A024293 Extended with signs Mar 1997
%E A024293 Prior Mathematica program replaced by _Harvey P. Dale_, May 21 2014