A282879 Number of nX2 0..1 arrays with no 1 equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element.

0, 2, 8, 32, 122, 416, 1414, 4626, 14930, 47432, 149032, 463918, 1432956, 4397436, 13419434, 40754026, 123245234, 371322718, 1115052844, 3338521720, 9969125698, 29697147320, 88271949298, 261856896380, 775373941754, 2292071140404

Offset: 1

Author

R. H. Hardin, Feb 24 2017

Keywords

• nonn

Comments

Column 2 of A282885.

Examples

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

Links

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

Crossrefs

Cf. A282885.

Formula

Empirical: a(n) = 2*a(n-1) +7*a(n-2) -2*a(n-3) -20*a(n-4) -24*a(n-5) -19*a(n-6) -14*a(n-7) -7*a(n-8) -2*a(n-9) -a(n-10).

Empirical: G.f.: 2*x^2*(2*x+1)*(x^3+x^2+1) / ( (x^5+x^4+3*x^3+4*x^2+x-1)^2 ). - R. J. Mathar, Mar 02 2017