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

1,3

Comments

Column 6 of A194193.

Links

Table of n, a(n) for n=1..20.

Example

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

Crossrefs

Sequence in context: A337309 A172386 A079233 * A190579 A271527 A214543

Adjacent sequences: A194188 A194189 A194190 * A194192 A194193 A194194

Keyword

nonn

Author

R. H. Hardin, Aug 18 2011

Status

approved