A303619 Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 12, 38, 148, 616, 2520, 10288, 42100, 172268, 704776, 2883500, 11797636, 48268920, 197487780, 808003420, 3305872824, 13525678764, 55339088836, 226414867352, 926355911364, 3790101263196, 15506855855704, 63444895485516

Offset

1,2

Comments

Column 3 of A303624.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A303624.

Sequence in context: A212510 A213490 A259517 * A167712 A209872 A186779

Adjacent sequences: A303616 A303617 A303618 * A303620 A303621 A303622

Keyword

nonn

Author

R. H. Hardin, Apr 27 2018

Status

approved