A300467 Number of n X 3 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

4, 29, 160, 925, 5363, 31106, 180397, 1046223, 6067629, 35189573, 204083997, 1183597158, 6864341406, 39810152164, 230881321531, 1339009818730, 7765666285883, 45037438874738, 261197278600938, 1514828996788371

Offset: 1

Author

R. H. Hardin, Mar 06 2018

Keywords

• nonn

Comments

Column 3 of A300472.

Examples

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

Links

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

Crossrefs

Cf. A300472.

Formula

Empirical: a(n) = 6*a(n-1) -a(n-2) -a(n-3) +a(n-4) -4*a(n-5) +a(n-6) -a(n-7).