A279460 Number of n X 2 0..1 arrays with no element equal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

0, 2, 6, 20, 66, 210, 658, 2036, 6236, 18928, 57032, 170790, 508748, 1508462, 4454576, 13107640, 38446722, 112448726, 328044512, 954771282, 2772970950, 8038036642, 23258558892, 67190053760, 193807573324, 558249440024, 1605908314802

Offset: 1

Author

R. H. Hardin, Dec 12 2016

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 2 of A279466.

Formula

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 3*a(n-4) - 14*a(n-5) - 14*a(n-6) - 14*a(n-7) - 13*a(n-8) - 6*a(n-9) - a(n-10).

Empirical g.f.: 2*x^2*(1 + x)*(1 - 2*x + 2*x^2 - 3*x^3 - x^4 - x^5 - x^6) / (1 - 2*x - x^2 - 2*x^3 - 3*x^4 - x^5)^2. - Colin Barker, Feb 11 2019