A304467 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero.

4, 21, 41, 117, 316, 810, 2208, 6012, 15837, 42579, 115618, 309144, 829935, 2246106, 6045980, 16264045, 43945153, 118607081, 319754491, 863718047, 2333646132, 6300949455, 17025299379, 46023642233, 124382811126, 336236258224

Offset

1,1

Comments

Column 3 of A304472.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +8*a(n-3) -21*a(n-4) -26*a(n-5) +10*a(n-6) +31*a(n-7) +20*a(n-8) -20*a(n-9) -10*a(n-10) for n>12

Example

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

Crossrefs

Cf. A304472.

Sequence in context: A110737 A273417 A273443 * A316284 A349807 A273405

Adjacent sequences: A304464 A304465 A304466 * A304468 A304469 A304470

Keyword

nonn

Author

R. H. Hardin, May 13 2018

Status

approved