A194191 Number of ways to arrange 6 indistinguishable points on an n X n square grid so that no three points are collinear at any angle.

0, 0, 2, 998, 36698, 620210, 5367308, 34678364, 169259212, 682686652, 2356999994, 7294368210, 20227526910, 52008171998, 124422857864, 279767468172, 596674510744, 1218556387684, 2385034544810, 4509309201242

Offset: 1

Author

R. H. Hardin, Aug 18 2011

Keywords

• nonn

Comments

Column 6 of A194193.

Examples

			Some solutions for 4 X 4:
..1..0..1..0....0..1..1..0....1..0..0..1....0..1..0..0....0..1..0..1
..0..0..0..1....1..0..0..0....0..0..1..1....0..0..1..1....0..0..0..1
..0..1..0..0....0..1..1..0....0..0..0..0....0..0..1..0....0..0..1..0
..0..0..1..1....1..0..0..0....0..1..1..0....1..0..0..1....1..0..1..0