A232042 Number of n X 3 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

4, 15, 80, 446, 2477, 13752, 76375, 424115, 2355221, 13079032, 72630752, 403334385, 2239803950, 12438120321, 69071597937, 383569664377, 2130046094920, 11828611039210, 65686859759121, 364773474308192, 2025666747456127

Offset: 1

Author

R. H. Hardin, Nov 17 2013

Keywords

• nonn

Examples

			Some solutions for n=7:
..1..1..0....1..1..0....0..0..1....1..1..0....1..0..0....1..1..1....1..1..0
..0..0..0....1..0..0....0..1..0....0..0..0....0..0..0....1..0..0....0..0..0
..1..1..0....1..1..1....1..0..0....0..1..0....0..0..0....0..1..0....0..0..0
..1..0..1....0..0..0....1..0..0....0..0..0....1..0..1....0..0..0....0..0..0
..0..1..0....0..0..0....0..1..0....1..1..1....0..1..1....1..0..0....1..1..1
..0..0..0....1..0..1....0..0..0....0..0..0....0..0..0....1..1..1....0..0..1
..0..0..0....0..1..1....0..0..1....1..0..0....0..0..0....0..0..0....0..1..1
		

Links

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

Crossrefs

Column 3 of A232047.

Formula

Empirical: a(n) = 4*a(n-1) + 9*a(n-2) -a (n-3) - 6*a(n-4) for n>5.

Empirical g.f.: x*(4 - x - 16*x^2 - 5*x^3 + 12*x^4) / (1 - 4*x - 9*x^2 + x^3 + 6*x^4). - Colin Barker, Oct 02 2018