A282641 Number of nX2 0..1 arrays with no 1 equal to more than one of its king-move neighbors.

4, 11, 27, 76, 201, 537, 1444, 3859, 10339, 27692, 74145, 198577, 531780, 1424091, 3813739, 10213132, 27350713, 73245065, 196149732, 525287779, 1406717235, 3767179500, 10088482321, 27016889761, 72351054724, 193755653291

Offset

1,1

Comments

Column 2 of A282647.

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) +4*a(n-3).

G.f.: -x*(4+7*x+4*x^2)/(-1+x+3*x^2+4*x^3) . - R. J. Mathar, Feb 28 2017

Example

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

Crossrefs

Cf. A282647.

Sequence in context: A266009 A096124 A269076 * A031127 A239031 A289217

Adjacent sequences: A282638 A282639 A282640 * A282642 A282643 A282644

Keyword

nonn

Author

R. H. Hardin, Feb 20 2017

Status

approved