A306048 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.

4, 21, 45, 142, 439, 1261, 3826, 11770, 35152, 106027, 323339, 977445, 2953775, 8969080, 27186554, 82305975, 249564286, 756677843, 2292774262, 6949799639, 21069414963, 63860628612, 193568100369, 586780928193, 1778655998433

Offset

1,1

Comments

Column 3 of A306053.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +9*a(n-3) -20*a(n-4) -27*a(n-5) +11*a(n-6) +33*a(n-7) +18*a(n-8) -22*a(n-9) -10*a(n-10) for n>12

Example

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

Crossrefs

Cf. A306053.

Sequence in context: A273405 A273831 A273847 * A266149 A042223 A317225

Adjacent sequences: A306045 A306046 A306047 * A306049 A306050 A306051

Keyword

nonn

Author

R. H. Hardin, Jun 18 2018

Status

approved