A317758 Number of nXn 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 6, 16, 43, 109, 266, 639, 1529, 3674, 8909, 21853, 54252, 136213, 345373, 882828, 2271143, 5871373, 15234214, 39633091, 103306417, 269641062, 704462713, 1841692605, 4816973880, 12602801545

Offset: 1

Author

R. H. Hardin, Aug 06 2018

Keywords

• nonn

Comments

Diagonal of A317764.

Examples

			Some solutions for n=5
..0..1..1..1..1. .0..1..1..1..1. .0..1..1..1..1. .0..0..0..0..0
..1..1..1..1..1. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..0..0
..0..0..0..0..0. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..0..0
..0..0..0..0..1. .1..1..1..1..1. .1..1..1..1..0. .0..0..0..0..0
..0..0..0..1..1. .0..0..0..0..0. .1..1..1..0..0. .0..0..0..0..1
		

Crossrefs

Cf. A317764.