A282522 Number of nX2 0..1 arrays with no 1 equal to more than two of its king-move neighbors.

4, 15, 43, 144, 473, 1529, 5004, 16335, 53283, 173960, 567801, 1853249, 6049204, 19744783, 64447643, 210360128, 686623961, 2241169033, 7315270172, 23877346447, 77936655891, 254388502200, 830334694009, 2710247124433, 8846359824580

Offset

1,1

Comments

Column 2 of A282528.

Links

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

Formula

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

Empirical: G.f.: -x*(-4-3*x+6*x^2+8*x^3)/(1-3*x-x^2-2*x^3+8*x^4) . - R. J. Mathar, Feb 28 2017

Example

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

Crossrefs

Cf. A282528.

Sequence in context: A213498 A294259 A240359 * A329523 A331317 A259664

Adjacent sequences: A282519 A282520 A282521 * A282523 A282524 A282525

Keyword

nonn

Author

R. H. Hardin, Feb 17 2017

Status

approved