A228749 Number of n X n binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally.

1, 3, 39, 780, 43862, 4823826, 1316714732, 762713002760, 1040109467257908, 3118624187066762728, 21501868781585259257676, 331091404725670052219822756, 11603262095526618070600084170304, 914315533886530112431287075923892544

Offset: 1

Author

R. H. Hardin Sep 02 2013

Keywords

• nonn

Comments

Diagonal of A228754

Examples

			Some solutions for n=4
..1..0..0..0....1..0..0..1....1..0..0..0....1..0..1..0....1..0..0..0
..1..0..0..0....0..1..0..0....0..0..0..1....0..0..1..0....1..0..1..0
..0..1..0..1....0..0..0..1....0..1..0..0....1..0..0..1....1..0..1..0
..0..1..0..0....1..0..0..0....0..1..0..1....0..0..0..0....1..0..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..30