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 A292497 #18 Sep 18 2017 19:25:15
%S A292497 1,0,0,0,1,0,6,0,20,5,258,62,2510,914,24285,16403,263945,222240,
%T A292497 3068971,3241157,35286928,46638022,426740187,650095127,5330192371,
%U A292497 9185814630,67064945191,129902075662,864443143567,1833530501143,11336065334984,25990268638322
%N A292497 Number of solutions to 1^2 +- 3^2 +- 5^2 +- 7^2 +- ... +- (4*n-1)^2 = 0.
%H A292497 Seiichi Manyama, <a href="/A292497/b292497.txt">Table of n, a(n) for n = 0..100</a>
%F A292497 For n>0 constant term in the expansion of 1/2 * Product_{k=1..2*n} (x^(2*k-1)^2+1/x^(2*k-1)^2).
%F A292497 a(n) = A292496(n)/2 for n>0.
%Y A292497 Cf. A083527, A156700, A292496.
%K A292497 nonn
%O A292497 0,7
%A A292497 _Seiichi Manyama_, Sep 17 2017