A301609 Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

0, 3, 62, 3816, 758338, 488491106, 1019565752074, 6897694015722898, 151249886315100454600, 10749578188598491367494716

Offset: 1

Author

R. H. Hardin, Mar 24 2018

Keywords

• nonn

Comments

Diagonal of A301615.

Examples

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

Crossrefs

Cf. A301615.