A268892 Number of 7Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 2285, 60666, 1706732, 39670270, 911930096, 19876401224, 426591159751, 8952723005030, 185650834624156, 3802871585155968, 77225962585267472, 1555913690406127580, 31149964203775581289, 620153220846869863058

Offset: 1

Author

R. H. Hardin, Feb 15 2016

Keywords

• nonn

Comments

Row 7 of A268886.

Examples

			Some solutions for n=3
..1..0..0. .0..1..1. .1..0..0. .0..0..1. .0..1..0. .0..0..0. .0..0..1
..0..0..1. .0..0..0. .1..1..0. .1..0..0. .0..1..0. .0..0..1. .1..0..0
..1..0..0. .1..0..1. .0..0..1. .0..0..0. .1..0..1. .1..0..1. .1..0..0
..1..0..0. .1..0..1. .1..0..0. .0..0..0. .1..0..0. .0..0..1. .0..1..0
..0..1..0. .0..0..0. .1..0..1. .0..1..1. .1..0..0. .0..1..0. .0..1..0
..1..0..0. .1..0..1. .0..0..1. .0..0..0. .1..0..1. .0..1..0. .1..0..1
..1..0..0. .0..0..1. .0..0..0. .0..1..0. .0..0..0. .0..0..1. .0..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210
• R. H. Hardin, Empirical recurrence of order 68

Crossrefs

Cf. A268886.

Formula

Empirical recurrence of order 68 (see link above)