A269269 Number of n X n 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once.

0, 108, 46872, 74853576, 542973139128, 19356924219624936, 3516906597130333936872, 3322606082327701612506093240, 16524782213263820847479975782463640

Offset: 1

Author

R. H. Hardin, Feb 21 2016

Keywords

• nonn

Comments

Diagonal of A269276.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..11

Crossrefs

Cf. A269276.