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 A298938 #5 Jan 29 2018 21:12:29
%S A298938 1,1,1,4,5,686,13942,455988,13617853,454222894,18323165948,
%T A298938 802161109047,42149084452070,2481730049781672,157265294178424356,
%U A298938 10977302934685469078,812821237985857557677,64539935903231450294134,5504599828399250884049308
%N A298938 Number of ordered ways of writing n^3 as a sum of n squares of nonnegative integers.
%H A298938 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%F A298938 a(n) = [x^(n^3)] (Sum_{k>=0} x^(k^2))^n.
%e A298938 a(4) = 5 because we have [64, 0, 0, 0], [16, 16, 16, 16], [0, 64, 0, 0], [0, 0, 64, 0] and [0, 0, 0, 64].
%t A298938 Table[SeriesCoefficient[(1 + EllipticTheta[3, 0, x])^n/2^n, {x, 0, n^3}], {n, 0, 18}]
%Y A298938 Cf. A000290, A000578, A006456, A030273, A037444, A066535, A218494, A232173, A287617, A298329, A298330, A298935, A298936, A298939.
%K A298938 nonn
%O A298938 0,4
%A A298938 _Ilya Gutkovskiy_, Jan 29 2018