A316284 Number of n X 3 0..1 arrays with every element unequal to 0, 1, 2, 3, 6 or 8 king-move adjacent elements, with upper left element zero.

4, 21, 42, 125, 361, 987, 2840, 8177, 23078, 66092, 189934, 542549, 1555968, 4472084, 12834117, 36874076, 106057815, 304978090, 877344581, 2525161569, 7268401508, 20925202372, 60256501068, 173532468268, 499807464421, 1439715507607

Offset

1,1

Comments

Column 3 of A316289.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +a(n-2) +6*a(n-3) -23*a(n-4) -22*a(n-5) +7*a(n-6) +27*a(n-7) +24*a(n-8) -18*a(n-9) -10*a(n-10) for n>12.

Example

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

Crossrefs

Cf. A316289.

Sequence in context: A273417 A273443 A304467 * A349807 A273405 A273831

Adjacent sequences: A316281 A316282 A316283 * A316285 A316286 A316287

Keyword

nonn

Author

R. H. Hardin, Jun 28 2018

Status

approved