A303011 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 20, 68, 308, 1320, 5220, 22652, 95220, 390580, 1662564, 6961252, 28957492, 122178532, 511463444, 2138409476, 8987766644, 37641997156, 157656704660, 661559870852, 2771791087028, 11615849382436, 48710299475156

Offset

1,1

Comments

Column 3 of A303016.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +4*a(n-2) +30*a(n-3) -88*a(n-4) -52*a(n-5) -84*a(n-6) -200*a(n-7) -80*a(n-8) -112*a(n-9) -96*a(n-10)

Example

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

Crossrefs

Cf. A303016.

Sequence in context: A123613 A006740 A291526 * A197426 A061981 A054611

Adjacent sequences: A303008 A303009 A303010 * A303012 A303013 A303014

Keyword

nonn

Author

R. H. Hardin, Apr 17 2018

Status

approved