A296535 Number of n X n 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 2 or 4 neighboring 1's.

1, 3, 16, 126, 2104, 78660, 5705431, 820373528, 239372827502, 141301759543525, 168080053760638246, 403684916425998696873

Offset: 1

Author

R. H. Hardin, Dec 15 2017

Keywords

• nonn

Comments

Diagonal of A296541.

Examples

			Some solutions for n=6
..0..1..0..0..0..0. .0..0..0..1..0..0. .0..0..0..1..1..0. .0..1..1..1..1..0
..1..1..0..1..1..0. .0..1..1..1..0..0. .0..0..1..0..1..0. .1..0..0..0..1..0
..0..0..1..0..1..0. .0..1..0..0..0..0. .0..1..0..0..1..0. .1..1..1..1..0..0
..0..1..0..0..1..0. .1..1..0..1..0..0. .0..1..0..0..1..1. .0..0..0..0..0..0
..1..0..1..1..0..0. .0..0..1..1..0..0. .1..0..0..0..0..1. .0..0..0..0..0..0
..1..1..0..0..0..0. .0..0..0..0..0..0. .1..1..1..1..1..0. .0..0..0..0..0..0
		

Crossrefs

Cf. A296541.