A269102 Number of n X n 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

4, 180, 40908, 43964700, 232068730044, 6206909793496236, 858502190008810133292, 622342168717398556687064028, 2386083493285894017930101786679468

Offset

1,1

Comments

Diagonal of A269109.

Links

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

Example

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

Crossrefs

Cf. A269109.

Sequence in context: A330771 A263436 A269195 * A240282 A278693 A172018

Adjacent sequences: A269099 A269100 A269101 * A269103 A269104 A269105

Keyword

nonn

Author

R. H. Hardin, Feb 19 2016

Status

approved