A316948 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

1, 25, 160, 1240, 9417, 71505, 543155, 4125662, 31337363, 238029974, 1808010056, 13733145621, 104313185951, 792334186609, 6018351922536, 45713741090407, 347228967561412, 2637455457327040, 20033384133349773, 152168059831839593

Offset

1,2

Comments

Column 3 of A316953.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +10*a(n-2) +15*a(n-3) +8*a(n-4) +3*a(n-5) +a(n-6) +2*a(n-7)

Example

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

Crossrefs

Cf. A316953.

Sequence in context: A049523 A232000 A260046 * A139729 A317728 A125335

Adjacent sequences: A316945 A316946 A316947 * A316949 A316950 A316951

Keyword

nonn

Author

R. H. Hardin, Jul 17 2018

Status

approved