A318070 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

4, 10, 18, 41, 81, 179, 404, 893, 2000, 4516, 10125, 22737, 51181, 115034, 258515, 581380, 1307094, 2938317, 6606445, 14853275, 33392840, 75076165, 168791772, 379483956, 853176349, 1918162541, 4312510121, 9695613622, 21798217755

Offset: 1

Author

R. H. Hardin, Aug 15 2018

Keywords

• nonn

Comments

Column 3 of A318075.

Examples

			Some solutions for n=5
..0..1..1. .0..0..0. .0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..0
..1..0..0. .0..0..0. .0..1..1. .1..1..1. .0..0..0. .0..0..0. .0..0..1
..1..1..0. .0..0..0. .1..1..1. .1..1..1. .0..0..1. .1..1..1. .0..1..1
..0..0..0. .0..1..0. .0..0..0. .1..0..1. .0..1..1. .1..1..1. .1..1..1
..0..0..1. .1..0..0. .0..0..1. .0..1..1. .1..1..0. .1..1..1. .0..0..0
		

Links

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

Crossrefs

Cf. A318075.

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) +a(n-3) -3*a(n-4) -6*a(n-5) +6*a(n-6) for n>10