A183443 Number of n X n binary arrays with every 1 having exactly two king-move neighbors equal to 1.

1, 5, 18, 72, 2054, 53608, 1744887, 216103851, 39184763856, 11314547102638, 7873316318240100, 9711485486581483616, 21262647899259681841579

Offset: 1

Author

R. H. Hardin Jan 04 2011

Keywords

• nonn

Comments

Diagonal of A183450

Examples

			Some solutions for 5X5
..0..0..0..0..0....0..0..0..1..0....0..0..1..0..0....0..1..0..0..0
..1..0..0..0..0....0..1..1..0..1....0..1..0..1..0....1..1..0..1..0
..1..1..0..1..1....1..0..0..0..1....1..0..0..0..1....0..0..0..1..1
..0..0..0..0..1....1..0..0..0..1....1..0..0..0..1....1..1..0..0..0
..0..0..0..0..0....0..1..1..1..0....0..1..1..1..0....0..1..0..0..0