A317378 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 5, 6, 7 or 8 king-move adjacent elements, with upper left element zero.

4, 5, 18, 36, 94, 270, 731, 1973, 5388, 14732, 40185, 109622, 299224, 816737, 2229029, 6083625, 16604273, 45318395, 123687970, 337583521, 921372891, 2514718793, 6863464096, 18732569928, 51127124540, 139542134747, 380854732742

Offset

1,1

Comments

Column 3 of A317383.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A317383.

Sequence in context: A026755 A368029 A243120 * A338866 A308485 A234143

Adjacent sequences: A317375 A317376 A317377 * A317379 A317380 A317381

Keyword

nonn

Author

R. H. Hardin, Jul 26 2018

Status

approved