A305687 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.

1, 25, 152, 1151, 8415, 61796, 453553, 3329201, 24436772, 179369495, 1316598259, 9664023496, 70935343213, 520675774985, 3821836201340, 28052835663739, 205911909175803, 1511423474214692, 11094068951867649, 81432085718227557

Offset

1,2

Comments

Column 3 of A305692.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +8*a(n-2) +12*a(n-3) +11*a(n-4) -a(n-5) +a(n-6) +a(n-7) -a(n-8)

Example

Some solutions for n=5
..0..1..1. .0..1..1. .0..0..0. .0..1..1. .0..0..1. .0..0..1. .0..1..1
..0..0..1. .0..1..0. .1..1..1. .0..1..0. .0..1..0. .1..1..1. .1..0..0
..1..0..0. .1..1..0. .1..1..1. .0..1..1. .1..1..0. .0..0..0. .0..1..1
..0..1..1. .0..0..0. .0..0..1. .0..1..0. .1..0..1. .1..0..0. .0..0..0
..0..0..1. .1..1..0. .0..1..0. .0..0..0. .1..0..1. .0..1..0. .0..1..0

Crossrefs

Cf. A305692.

Sequence in context: A042214 A215760 A362314 * A147059 A317067 A031211

Adjacent sequences: A305684 A305685 A305686 * A305688 A305689 A305690

Keyword

nonn

Author

R. H. Hardin, Jun 08 2018

Status

approved