A304664 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 5 or 6 king-move adjacent elements, with upper left element zero.

3, 9, 13, 30, 66, 123, 252, 535, 1074, 2194, 4530, 9231, 18873, 38722, 79180, 161992, 331766, 678927, 1389398, 2844206, 5821252, 11914196, 24386446, 49913147, 102159115, 209097391, 427973147, 875956927, 1792880557, 3669604702

Offset

1,1

Comments

Column 3 of A304669.

Links

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

Formula

Empirical: a(n) = a(n-1) +4*a(n-3) +2*a(n-5) -a(n-7) -2*a(n-9) -2*a(n-11) -a(n-12)

Example

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

Crossrefs

Cf. A304669.

Sequence in context: A304350 A305913 A215443 * A068885 A305644 A316920

Adjacent sequences: A304661 A304662 A304663 * A304665 A304666 A304667

Keyword

nonn

Author

R. H. Hardin, May 16 2018

Status

approved