A303956 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 5 king-move adjacent elements, with upper left element zero.

4, 5, 11, 22, 49, 119, 287, 664, 1563, 3716, 8788, 20753, 49077, 116121, 274644, 649499, 1536206, 3633554, 8594035, 20326437, 48076235, 113710340, 268947851, 636115892, 1504543784, 3558552569, 8416699677, 19907205269, 47084589648

Offset

1,1

Comments

Column 3 of A303961.

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +3*a(n-3) +2*a(n-4) -2*a(n-5) -6*a(n-6) -4*a(n-7) for n>8

Example

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

Crossrefs

Cf. A303961.

Sequence in context: A227620 A036539 A279710 * A000769 A246495 A050831

Adjacent sequences: A303953 A303954 A303955 * A303957 A303958 A303959

Keyword

nonn

Author

R. H. Hardin, May 03 2018

Status

approved