A306161 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

4, 5, 17, 32, 77, 207, 523, 1304, 3307, 8414, 21308, 53961, 136813, 346873, 879204, 2228553, 5649254, 14320348, 36300091, 92016267, 233250975, 591264096, 1498784411, 3799243014, 9630638220, 24412541681, 61882935885, 156866006985

Offset

1,1

Comments

Column 3 of A306166.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A306166.

Sequence in context: A026869 A350662 A061806 * A119997 A010361 A327683

Adjacent sequences: A306158 A306159 A306160 * A306162 A306163 A306164

Keyword

nonn

Author

R. H. Hardin, Jun 23 2018

Status

approved