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 A226558 #25 Jul 07 2023 14:36:23
%S A226558 64,1984,23232,153824,724352,2661504,8208640,22114304,53570368,
%T A226558 119129856,246971072,482429024,896290944,1594476160,2732250688,
%U A226558 4529267712,7292346816,11438236320,17528382400,26300206624
%N A226558 Number of equilateral triangles with coordinates (w,x,y,z) in the set {0, 1,...,n}.
%H A226558 Ray Chandler, <a href="/A226558/b226558.txt">Table of n, a(n) for n = 1..100</a>
%H A226558 Eugen J. Ionascu, <a href="http://arxiv.org/abs/1209.0147">Equilateral triangles in Z^4</a>, arXiv:1209.0147 [math.NT].
%Y A226558 Cf. A102698.
%K A226558 nonn
%O A226558 1,1
%A A226558 _Ray Chandler_, Jun 10 2013