Details

For more information, see:

E. J. Ionascu, "A Parametrization of Equilateral Triangles Having Integer Coordinates," Journal of Integer Sequences, 10(6), 2007 Article 07.6.7, www.cs.uwaterloo.ca/journals/JIS.

E. J. Ionascu, "Counting All Equilateral Triangles in {0, 1, ..., n}^3," math.colstate.edu/ejionascu. (Oct 18, 2007)

"Number of Equilateral Triangles with Coordinates (x, y, z) in the Set {0, 1, ..., n}," (sequence A102698), in The On-Line Encyclopedia of Integer Sequences (copyright N. J. A. Sloane), www.research.att.com/~njas/sequences. (Oct 18, 2007)