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

1,2

Comments

Diagonal of A301615.

Links

Table of n, a(n) for n=1..10.

Example

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.

Sequence in context: A275746 A177496 A104403 * A144422 A327053 A135444

Adjacent sequences: A301606 A301607 A301608 * A301610 A301611 A301612

Keyword

nonn

Author

R. H. Hardin, Mar 24 2018

Status

approved