A300420 Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 3, 53, 2227, 240196, 67378450, 48707694395, 90693182026546, 435112536711313866, 5381527099060030118335, 171582103150798864303410622

Offset

1,2

Comments

Diagonal of A300427.

Links

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

Example

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

Crossrefs

Cf. A300427.

Sequence in context: A012823 A098932 A100444 * A300683 A296678 A227051

Adjacent sequences: A300417 A300418 A300419 * A300421 A300422 A300423

Keyword

nonn

Author

R. H. Hardin, Mar 05 2018

Status

approved