A268988 Number of n X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

2, 13, 174, 6009, 421450, 66954420, 22995344760, 17373640598542, 29082748697180602, 107300241515211644436, 883523091936988991189604, 16140842052133986432421342048, 659806253617230823177640504040304

Offset: 1

Author

R. H. Hardin, Feb 17 2016

Keywords

• nonn

Comments

Diagonal of A268995.

Examples

			Some solutions for n=4
..0..1..0..1. .0..0..1..0. .1..1..0..1. .0..0..0..1. .0..0..0..0
..0..1..0..0. .0..0..0..0. .0..1..0..0. .0..1..0..0. .0..0..1..0
..0..0..1..1. .1..0..0..0. .0..0..1..0. .0..0..0..1. .1..0..1..0
..0..0..0..0. .0..0..1..1. .0..0..0..1. .0..1..0..0. .1..0..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..26

Crossrefs

Cf. A268995.