A303416 Number of n X 3 0..1 arrays with every element equal to 0, 1, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 32, 252, 1988, 15684, 123732, 976132, 7700788, 60752164, 479278932, 3781071812, 29829193588, 235325017444, 1856498858132, 14646075660292, 115544122910388, 911537305199524, 7191194479141332, 56731938168469572, 447563032495731188

Offset

1,1

Comments

Column 3 of A303421.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +6*a(n-2) +8*a(n-3).

Example

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

Crossrefs

Cf. A303421.

Sequence in context: A273053 A303422 A301402 * A007278 A108449 A213413

Adjacent sequences: A303413 A303414 A303415 * A303417 A303418 A303419

Keyword

nonn

Author

R. H. Hardin, Apr 23 2018

Status

approved