A194192 Number of ways to arrange 7 indistinguishable points on an n X n square grid so that no three points are collinear at any angle.

0, 0, 0, 204, 26700, 1073076, 15657764, 159413700, 1108580092, 6030207624, 26852315940, 104865006648, 354993232192, 1098793355508, 3109294280324

Offset

1,4

Comments

Column 7 of A194193.

Links

Table of n, a(n) for n=1..15.

Example

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

Crossrefs

Sequence in context: A253680 A209790 A348603 * A339199 A263505 A270605

Adjacent sequences: A194189 A194190 A194191 * A194193 A194194 A194195

Keyword

nonn

Author

R. H. Hardin, Aug 18 2011

Status

approved