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 A229295 #13 Aug 07 2018 17:49:40
%S A229295 4,24,36,32,100,216,196,192,396,600,484,288,676,1176,900,256,1156,
%T A229295 2376,1444,800,1764,2904,2116,1728,2900,4056,3564,1568,3364,5400,3844,
%U A229295 1536,4356,6936,4900,3168,5476,8664,6084,4800,6724,10584,7396,3872,9900,12696
%N A229295 Number of solutions to x^2 + y^2 + z^2 == n (mod 2n) for x,y,z in [0, 2*n).
%C A229295 All values are divisible by a(1)=4 and the sequence a(n)/4 is multiplicative. - _Andrew Howroyd_, Aug 07 2018
%H A229295 Andrew Howroyd, <a href="/A229295/b229295.txt">Table of n, a(n) for n = 1..2500</a>
%F A229295 a(n) = 4*A087687(n) for odd n, a(4^k) = 4*2^(3*k), a(2*4^k) = 24*2^(3*k). - _Andrew Howroyd_, Aug 07 2018
%t A229295 A[n_] := Sum[If[Mod[a^2 + b^2 + c^2, 2*n] == n, 1, 0], {a, 0, 2*n - 1}, {b, 0, 2*n - 1}, {c, 0, 2*n - 1}]; Array[A,100]
%o A229295 (PARI) a(n)={my(m=2*n); my(p=Mod(sum(i=0, m-1, x^(i^2%m)), x^m-1)^3); polcoeff( lift(p), n)} \\ _Andrew Howroyd_, Aug 06 2018
%o A229295 (PARI) a(n)={my(f=factor(n)); 4*prod(i=1, #f~, my([p, e]=f[i, ]); if(p==2, if(e%2, 3, 1)*2^(e+e\2), p^(e+(e-1)\2)*(p^(e\2)*(p+1) - 1)))} \\ _Andrew Howroyd_, Aug 07 2018
%Y A229295 Cf. A087687, A229294, A229296, A229297.
%K A229295 nonn
%O A229295 1,1
%A A229295 _José María Grau Ribas_, Sep 22 2013