A303891 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

1, 23, 54, 271, 842, 3420, 11916, 45404, 163979, 611654, 2237701, 8282518, 30442766, 112364696, 413696068, 1525420791, 5619579530, 20713550451, 76324380196, 281291917100, 1036573413060, 3820089888616, 14077601589105, 51879385009658

Offset

1,2

Comments

Column 3 of A303896.

Links

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

Formula

Empirical: a(n) = a(n-1) +10*a(n-2) +4*a(n-3) -13*a(n-4) -13*a(n-5) +8*a(n-6) -7*a(n-7) -13*a(n-8) -6*a(n-9) -4*a(n-10) +a(n-11) -5*a(n-12) +2*a(n-13) for n>14

Example

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

Crossrefs

Cf. A303896.

Sequence in context: A103006 A053236 A118603 * A264117 A033657 A305283

Adjacent sequences: A303888 A303889 A303890 * A303892 A303893 A303894

Keyword

nonn

Author

R. H. Hardin, May 02 2018

Status

approved