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 A320240 #13 Feb 16 2025 08:33:56
%S A320240 1,2,0,2,6,2,4,6,8,14,4,12,18,12,12,8,34,12,8,32,10,28,0,16,44,18,16,
%T A320240 14,54,8,12,48,32,52,28,32,42,40,8,44,92,28,16,56,28,30,44,12,86,74,8,
%U A320240 32,72,24,40,104,72,56,32,56,56,112,8,38,166,24,36,40,56,88,52
%N A320240 Expansion of theta_3(q) * theta_3(q^3) * theta_3(q^5) * theta_3(q^7), where theta_3() is the Jacobi theta function.
%C A320240 Also the number of integer solutions (a_1, a_2, a_3, a_4) to the equation a_1^2 + 3*a_2^2 + 5*a_3^2 + 7*a_4^2 = n.
%H A320240 Seiichi Manyama, <a href="/A320240/b320240.txt">Table of n, a(n) for n = 0..10000</a>
%H A320240 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/JacobiThetaFunctions.html">Jacobi Theta Functions</a>
%Y A320240 Product_{k=1..m} theta_3(q^(2*k-1)): A000122 (m=1), A033716 (m=2), A320239 (m=3), this sequence (m=4).
%Y A320240 Cf. A320078.
%K A320240 nonn
%O A320240 0,2
%A A320240 _Seiichi Manyama_, Oct 08 2018