A304599 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 5 or 6 king-move adjacent elements, with upper left element zero.

4, 5, 13, 23, 53, 131, 330, 793, 1930, 4765, 11686, 28627, 70237, 172374, 422930, 1037573, 2545757, 6246392, 15325889, 37602947, 92261907, 226372036, 555420895, 1362767425, 3343655704, 8203918429, 20128946224, 49387923264, 121177087505

Offset

1,1

Comments

Column 3 of A304604.

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +4*a(n-3) +2*a(n-4) -2*a(n-5) -7*a(n-6) -6*a(n-7) for n>10

Example

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

Crossrefs

Cf. A304604.

Sequence in context: A147001 A247325 A140683 * A071341 A272898 A102981

Adjacent sequences: A304596 A304597 A304598 * A304600 A304601 A304602

Keyword

nonn

Author

R. H. Hardin, May 15 2018

Status

approved