A316803 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.

4, 32, 247, 1905, 14711, 113606, 877309, 6774916, 52318510, 404023677, 3120026371, 24094044759, 186063489168, 1436853892633, 11095938907760, 85687111874080, 661708865050287, 5109970595456477, 39461160134896235, 304734270012530218

Offset

1,1

Comments

Column 3 of A316808.

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -3*a(n-2) +7*a(n-3) -3*a(n-4)

Example

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

Crossrefs

Cf. A316808.

Sequence in context: A301779 A370044 A147551 * A299649 A317520 A300203

Adjacent sequences: A316800 A316801 A316802 * A316804 A316805 A316806

Keyword

nonn

Author

R. H. Hardin, Jul 14 2018

Status

approved