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 A303170 #6 Feb 16 2025 08:33:54
%S A303170 1,1,1,1,5,21,61,141,309,757,2111,6051,16721,44617,118301,318501,
%T A303170 871781,2400741,6596953,18067329,49460555,135697395,373271515,
%U A303170 1028451579,2835353337,7819016521,21572619771,59562583471,164586609409,455114644297,1259191262441,3485551053561
%N A303170 Number of ordered ways of writing n as a sum of n tetrahedral numbers.
%H A303170 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TetrahedralNumber.html">Tetrahedral Number</a>
%H A303170 <a href="/index/Ps#pyramidal_numbers">Index to sequences related to pyramidal numbers</a>
%F A303170 a(n) = [x^n] (Sum_{k>=0} x^(k*(k+1)*(k+2)/6))^n.
%F A303170 a(n) = A290429(n,n).
%t A303170 Table[SeriesCoefficient[Sum[x^(k (k + 1) (k + 2)/6), {k, 0, n}]^n, {x, 0, n}], {n, 0, 31}]
%Y A303170 Main diagonal of A290429.
%Y A303170 Cf. A000292, A068980, A106337, A282582, A303172.
%K A303170 nonn
%O A303170 0,5
%A A303170 _Ilya Gutkovskiy_, Apr 19 2018