A303177 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 17, 31, 135, 547, 1938, 6965, 25953, 95602, 350544, 1288829, 4742540, 17436564, 64107857, 235741082, 866860297, 3187480223, 11720639783, 43098018497, 158475393298, 582728318557, 2142746395133, 7879078188002, 28972099906592

Offset

1,1

Comments

Column 3 of A303182.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +12*a(n-3) +4*a(n-4) -14*a(n-5) -17*a(n-6) -26*a(n-7) +52*a(n-8) -8*a(n-10) +8*a(n-12) -32*a(n-13)

Example

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

Crossrefs

Cf. A303182.

Sequence in context: A249582 A127547 A302410 * A212756 A031040 A273675

Adjacent sequences: A303174 A303175 A303176 * A303178 A303179 A303180

Keyword

nonn

Author

R. H. Hardin, Apr 19 2018

Status

approved