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 A293287 #12 Oct 06 2017 18:33:17
%S A293287 1,-1,-2,3,-1,-5,9,3,-20,16,20,-54,19,89,-123,-56,287,-181,-383,748,
%T A293287 37,-1520,1406,1619,-4439,1190,7768,-10102,-5494,25673,-14754,-36660,
%U A293287 66367,7047,-139852,125785,153573,-405349,98671,712275,-909382,-514965,2332540,-1303341
%N A293287 G.f.: Product_{m>0} 1/(1 + x^m + 2!*x^(2*m)).
%H A293287 Seiichi Manyama, <a href="/A293287/b293287.txt">Table of n, a(n) for n = 0..500</a>
%F A293287 Convolution inverse of A293204.
%o A293287 (PARI) Vec(prod(m=1, 50, 1/(1 + x^m + 2!*x^(2*m))) + O(x^50)) \\ _Michel Marcus_, Oct 05 2017
%Y A293287 Column k=2 of A293285.
%Y A293287 Cf. A293204.
%K A293287 sign
%O A293287 0,3
%A A293287 _Seiichi Manyama_, Oct 04 2017