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 A303172 #5 Feb 16 2025 08:33:54
%S A303172 1,1,1,1,1,6,31,106,281,631,1306,2806,6931,19306,55070,150816,391161,
%T A303172 977501,2426071,6141865,16000186,42465571,112950916,297793651,
%U A303172 776866355,2015237231,5233754306,13668689206,35908153534,94633042267,249398115466,656105299636,1723150461561
%N A303172 Number of ordered ways of writing n as a sum of n square pyramidal numbers.
%H A303172 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquarePyramidalNumber.html">Square Pyramidal Number</a>
%H A303172 <a href="/index/Ps#pyramidal_numbers">Index to sequences related to pyramidal numbers</a>
%F A303172 a(n) = [x^n] (Sum_{k>=0} x^(k*(k+1)*(2*k+1)/6))^n.
%F A303172 a(n) = A290430(n,n).
%t A303172 Table[SeriesCoefficient[Sum[x^(k (k + 1) (2 k + 1)/6), {k, 0, n}]^n, {x, 0, n}], {n, 0, 32}]
%Y A303172 Main diagonal of A290430.
%Y A303172 Cf. A000330, A066535, A279220, A287617, A303170.
%K A303172 nonn
%O A303172 0,6
%A A303172 _Ilya Gutkovskiy_, Apr 19 2018