A269195 Number of n X n 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three no more than once.

4, 180, 25572, 15289548, 34838403756, 320994710282892, 12093315071771856492, 1887658657444603460395332, 1230222115345954315761363474780, 3366670969596963372379333414861881876

Offset: 1

Author

R. H. Hardin, Feb 20 2016

Keywords

• nonn

Comments

Diagonal of A269201.

Examples

			Some solutions for n=3
..0..2..0. .0..1..0. .3..1..3. .0..0..1. .1..0..0. .3..1..2. .0..0..0
..0..1..3. .1..1..1. .0..3..3. .0..0..1. .1..0..1. .3..2..0. .2..0..0
..0..1..3. .3..1..3. .3..1..1. .0..1..0. .3..3..1. .2..2..0. .2..0..1
		

Crossrefs

Cf. A269201.