A304265 Number of nX3 0..1 arrays with every element unequal to 0, 1, 5 or 8 king-move adjacent elements, with upper left element zero.

3, 3, 6, 10, 19, 37, 67, 124, 235, 436, 808, 1513, 2821, 5245, 9784, 18247, 33982, 63334, 118075, 220021, 410023, 764248, 1424311, 2654380, 4947124, 9220057, 17183197, 32024569, 59684740, 111234331, 207308038, 386362258, 720065251, 1341989365

Offset

1,1

Comments

Column 3 of A304270.

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-3) for n>4

Example

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

Crossrefs

Cf. A304270.

Sequence in context: A300301 A031504 A298164 * A049871 A049924 A049926

Adjacent sequences: A304262 A304263 A304264 * A304266 A304267 A304268

Keyword

nonn

Author

R. H. Hardin, May 09 2018

Status

approved