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 A298330 #9 Dec 16 2024 13:29:22
%S A298330 1,1,0,3,1,5,141,742,6120,43888,300232,3074478,28901797,290411147,
%T A298330 3175037698,34951274416,399750066121,4814421349467,59532792202344,
%U A298330 768079420764884,10247011240209066,140144002390928732,1978092111496441512,28633995987157024399
%N A298330 Number of ordered ways of writing n^2 as a sum of n squares of positive integers.
%H A298330 Robert Israel, <a href="/A298330/b298330.txt">Table of n, a(n) for n = 0..100</a>
%H A298330 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%F A298330 a(n) = [x^(n^2)] (Sum_{k>=1} x^(k^2))^n.
%e A298330 a(3) = 3 because we have [4, 4, 1], [4, 1, 4] and [1, 4, 4].
%p A298330 G:= (JacobiTheta3(0,x)-1)/2:
%p A298330 f:= proc(n) local S; S:= series(G^n,x,n^2+1); coeff(S,x,n^2) end proc:
%p A298330 map(f, [$0..25]); # _Robert Israel_, Dec 16 2024
%t A298330 Table[SeriesCoefficient[(-1 + EllipticTheta[3, 0, x])^n/2^n, {x, 0, n^2}], {n, 0, 23}]
%Y A298330 Cf. A037444, A066535, A232173, A287617, A298329.
%K A298330 nonn
%O A298330 0,4
%A A298330 _Ilya Gutkovskiy_, Jan 17 2018