A302219 Number of n X 3 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 14, 43, 194, 675, 2666, 9819, 37382, 140039, 528962, 1989787, 7501790, 28252719, 106464314, 401084083, 1511229542, 5693728487, 21452605794, 80826937611, 304534567726, 1147401249247, 4323099142602, 16288258059235, 61369756239670

Offset

1,2

Comments

Column 3 of A302224.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +7*a(n-2) -5*a(n-3) -34*a(n-4) -46*a(n-5) +64*a(n-6) +112*a(n-7) +60*a(n-8) -96*a(n-9) -80*a(n-10) -64*a(n-11).

Example

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

Crossrefs

Cf. A302224.

Sequence in context: A242897 A120714 A041378 * A302665 A041380 A151990

Adjacent sequences: A302216 A302217 A302218 * A302220 A302221 A302222

Keyword

nonn

Author

R. H. Hardin, Apr 03 2018

Status

approved