A301945 Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

0, 2, 20, 947, 120815, 58609226, 86143630040, 418568449327270, 6527100767589040926, 331808147283786972146018, 54543586667142977292165721500, 29084806316831133817614992597097070

Offset: 1

Author

R. H. Hardin, Mar 29 2018

Keywords

• nonn

Comments

Diagonal of A301951.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..13

Crossrefs

Cf. A301951.