A282642 Number of n X 3 0..1 arrays with no 1 equal to more than one of its king-move neighbors.

7, 27, 99, 413, 1601, 6349, 25153, 99287, 392907, 1553391, 6142251, 24289277, 96042921, 379779797, 1501741049, 5938235583, 23481235283, 92850420759, 367152906387, 1451810964181, 5740809545409, 22700542022605, 89763402870129

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 6*a(n-2) + 8*a(n-3) - 5*a(n-4) + 2*a(n-5) - 2*a(n-6).

Empirical g.f.: x*(7 + 13*x + 3*x^2 - 3*x^3 - 2*x^5) / (1 - 2*x - 6*x^2 - 8*x^3 + 5*x^4 - 2*x^5 + 2*x^6). - Colin Barker, Feb 20 2019

Example

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

Crossrefs

Column 3 of A282647.

Sequence in context: A135914 A213588 A305653 * A185080 A006350 A054485

Adjacent sequences: A282639 A282640 A282641 * A282643 A282644 A282645

Keyword

nonn

Author

R. H. Hardin, Feb 20 2017

Status

approved