A282051 Number of n X 2 0..2 arrays with no element unequal to more than four of its king-move neighbors and with new values introduced in order 0 sequentially upwards.

2, 14, 91, 600, 4039, 27212, 183195, 1233336, 8303647, 55905604, 376392451, 2534116400, 17061305479, 114867707132, 773363450795, 5206781283496, 35055408051567, 236015604782644, 1589009194201811, 10698234218839200

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - 11*a(n-2) + 20*a(n-3) - 24*a(n-4) + 8*a(n-5).

Empirical g.f.: x*(1 - 2*x)*(2 + 2*x + 5*x^2 - 4*x^3) / ((1 - x)*(1 - 7*x + 4*x^2 - 16*x^3 + 8*x^4)). - Colin Barker, Feb 20 2019

Example

Some solutions for n=4:
..0..1. .0..0. .0..0. .0..0. .0..1. .0..1. .0..1. .0..1. .0..1. .0..1
..1..0. .1..0. .1..0. .1..0. .2..2. .0..1. .2..1. .0..2. .1..2. .1..0
..1..0. .0..1. .0..1. .1..2. .1..2. .0..0. .2..2. .2..2. .1..2. .2..1
..0..1. .2..2. .0..2. .2..2. .1..1. .1..2. .0..1. .1..0. .0..1. .1..2

Crossrefs

Column 2 of A282056.

Sequence in context: A109113 A081959 A002464 * A020063 A323561 A288470

Adjacent sequences: A282048 A282049 A282050 * A282052 A282053 A282054

Keyword

nonn

Author

R. H. Hardin, Feb 05 2017

Status

approved