A317521 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.

8, 128, 1921, 28760, 431529, 6475106, 97158833, 1457871738, 21875422403, 328241570548, 4925277664965, 73903984966452, 1108932199510127, 16639571244859588, 249677420617443179, 3746419510986492706

Offset

1,1

Comments

Column 4 of A317525.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) +a(n-2) -8*a(n-3) -84*a(n-4) -63*a(n-5) +24*a(n-6) +20*a(n-7)

Example

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

Crossrefs

Cf. A317525.

Sequence in context: A301780 A348804 A316804 * A299650 A300204 A213414

Adjacent sequences: A317518 A317519 A317520 * A317522 A317523 A317524

Keyword

nonn

Author

R. H. Hardin, Jul 30 2018

Status

approved