A268910 Number of 7Xn 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 159744, 5038848, 154472184, 4513169016, 129834259704, 3679171151832, 103095286509168, 2860978283523432, 78747017051741472, 2152203067541169000, 58462727175138511872, 1579670961301113123600, 42485047384554878027688

Offset: 1

Author

R. H. Hardin, Feb 15 2016

Keywords

• nonn

Comments

Row 7 of A268904.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210
• R. H. Hardin, Empirical recurrence of order 54

Crossrefs

Cf. A268904.

Formula

Empirical recurrence of order 54 (see link above)