A268791 Number of n X n 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

0, 22, 248, 4800, 168740, 11138352, 1384570516, 325815151556, 145913571668076, 124768928833331732, 204377241703937153076, 642788798787566885184552, 3889478620658657294120765368, 45350632160719542617837369658508

Offset: 1

Author

R. H. Hardin, Feb 13 2016

Keywords

• nonn

Comments

Diagonal of A268798.

Examples

			Some solutions for n=4
..1..0..0..0. .2..1..2..1. .2..2..1..0. .1..2..1..2. .2..2..2..1
..1..0..1..0. .2..2..2..2. .1..0..0..0. .2..2..2..2. .2..1..2..2
..0..0..0..0. .2..2..2..2. .0..1..0..1. .2..1..2..1. .2..2..2..1
..1..0..0..0. .1..2..1..1. .0..0..0..0. .2..1..2..2. .2..2..2..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..18

Crossrefs

Cf. A268798.