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 A369729 #7 Jan 30 2024 11:42:11
%S A369729 0,1,1,2,5,13,38,118,380,1262,4277,14745,51541,182182,650095,2338706,
%T A369729 8472697,30884150,113189168,416839177,1541726967,5724470097,
%U A369729 21330062502,79733319862,298922247363,1123678419818,4234465089737,15993581636893,60535561889465
%N A369729 Number of solutions to +- 1 +- 3 +- 5 +- 7 +- ... +- (4*n-3) = 1.
%F A369729 a(n) = [x^1] Product_{k=1..2*n-1} (x^(2*k-1) + 1/x^(2*k-1)).
%t A369729 Table[Coefficient[Product[(x^(2 k - 1) + 1/x^(2 k - 1)), {k, 1, 2 n - 1}], x, 1], {n, 0, 27}]
%Y A369729 Cf. A005408, A063866, A156700, A292476, A367087.
%K A369729 nonn
%O A369729 0,4
%A A369729 _Ilya Gutkovskiy_, Jan 30 2024