Triangle count in isometric grid
- Autor:
- Zbynek Konecny
Find the number of equilateral triangles with vertices in an equilateral triangular array of points with n rows (offset 1), with any orientation.
See also Original solution by Ignacio Larrosa Cañestro and OEIS A000332
Based on https://twitter.com/ilarrosac/status/1089123301522370561