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

1,2

Comments

Column 2 of A282885.

Links

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

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

Example

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

Crossrefs

Cf. A282885.

Sequence in context: A099752 A230393 A230529 * A217665 A337863 A324568

Adjacent sequences: A282876 A282877 A282878 * A282880 A282881 A282882

Keyword

nonn

Author

R. H. Hardin, Feb 24 2017

Status

approved