A316927 Number of n X 3 0..1 arrays with every element unequal to 0, 2, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 8, 25, 143, 851, 5114, 31197, 191330, 1175122, 7224809, 44437623, 273364775, 1681777472, 10346885271, 63658582520, 391658145868, 2409675958077, 14825545328503, 91214305480541, 561197004289508, 3452771040560531

Offset

1,2

Comments

Column 3 of A316932.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -3*a(n-2) -3*a(n-3) -64*a(n-4) -24*a(n-5) +77*a(n-6) +105*a(n-7) +88*a(n-8) -14*a(n-9) -40*a(n-10) +10*a(n-11) +18*a(n-12) +4*a(n-13) for n > 15.

Example

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

Crossrefs

Cf. A316932.

Sequence in context: A302617 A042189 A305680 * A004246 A362276 A220535

Adjacent sequences: A316924 A316925 A316926 * A316928 A316929 A316930

Keyword

nonn

Author

R. H. Hardin, Jul 16 2018

Status

approved