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