A206988 Number of n X n 0..1 arrays avoiding 0 0 0 horizontally and 1 1 1 vertically.

2, 16, 174, 6510, 516724, 88819714, 37849652838, 36679559167444, 82039130470188394, 429029852979061855882, 5194153238714571994969836, 145816870651378340099973452074

Offset: 1

Author

R. H. Hardin Feb 14 2012

Keywords

• nonn

Comments

Diagonal of A206994

Examples

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