A268897 Number of n X n 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 36, 1584, 118584, 17194680, 5344944120, 3679171151832, 5729028666080112, 20420870331077074152, 167959998252207918469944, 3205098856567970748329302728, 142456755446316393140675874983544

Offset: 1

Author

R. H. Hardin, Feb 15 2016

Keywords

• nonn

Comments

Diagonal of A268904.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..15

Crossrefs

Cf. A268904.