A231518 Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.

4, 34, 153, 776, 3861, 18721, 91993, 453274, 2223662, 10915727, 53635324, 263420767, 1293604417, 6353594215, 31205396110, 153258629442, 752708346275, 3696838244354, 18156489259107, 89173024237567, 437961215793703

Offset: 1

Author

R. H. Hardin, Nov 10 2013

Keywords

• nonn

Comments

Column 3 of A231523

Examples

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

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -2*a(n-2) +43*a(n-3) -50*a(n-4) +33*a(n-5) -307*a(n-6) +115*a(n-7) -66*a(n-8) +490*a(n-9) +60*a(n-10) -144*a(n-11) +32*a(n-12) -192*a(n-13) for n>14