A281797 Number of nX3 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 6, 75, 324, 865, 2272, 5191, 11141, 22705, 44611, 85366, 160212, 296306, 541784, 981579, 1764938, 3153155, 5602160, 9905073, 17437719, 30580597, 53442733, 93101164, 161719796, 280165812, 484172898, 834830159, 1436409132, 2466624753

Offset: 1

Author

R. H. Hardin, Jan 30 2017

Keywords

• nonn

Comments

Column 3 of A281802.

Examples

			Some solutions for n=4
..0..0..0. .0..1..0. .0..0..0. .0..1..1. .0..0..0. .0..0..1. .0..1..1
..0..0..1. .0..0..1. .1..0..0. .0..0..1. .0..0..1. .0..1..1. .1..0..1
..0..1..0. .0..0..0. .0..1..1. .1..0..0. .0..0..1. .1..0..1. .1..1..0
..0..0..1. .0..0..0. .1..0..0. .0..0..0. .0..0..0. .1..1..1. .1..0..0
		

Links

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

Crossrefs

Cf. A281802.

Formula

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +5*a(n-3) +12*a(n-4) -12*a(n-5) -3*a(n-6) +6*a(n-7) -a(n-9) for n>16