A302218 Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

0, 3, 43, 934, 40395, 3420704, 553097760, 177191137344, 102914156897887, 122108799039662692

Offset

1,2

Comments

Diagonal of A302224.

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..1..1..0. .0..0..0..1..1
..1..1..1..1..1. .1..1..0..0..1. .1..1..1..0..1. .1..0..1..0..1
..1..0..0..0..1. .1..1..1..1..1. .0..0..0..1..0. .0..1..1..0..0
..0..1..1..1..0. .0..0..0..0..0. .1..1..0..1..1. .0..0..0..1..0
..1..0..0..0..0. .0..1..1..1..0. .0..0..1..1..1. .1..1..1..1..1

Crossrefs

Cf. A302224.

Sequence in context: A141060 A361878 A277496 * A302664 A201784 A364498

Adjacent sequences: A302215 A302216 A302217 * A302219 A302220 A302221

Keyword

nonn

Author

R. H. Hardin, Apr 03 2018

Status

approved