A317371 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 6, 7 or 8 king-move adjacent elements, with upper left element zero.

1, 23, 91, 529, 2870, 15382, 83982, 455180, 2470224, 13414200, 72799534, 395190412, 2145176236, 11644256732, 63207599222, 343101702044, 1862418510584, 10109551780216, 54876478924754, 297879564777320, 1616944643352828

Offset

1,2

Comments

Column 3 of A317376.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +12*a(n-2) +15*a(n-3) -42*a(n-4) -28*a(n-5) +16*a(n-6) +4*a(n-7) -41*a(n-8) -5*a(n-9) +66*a(n-10) +45*a(n-11) -2*a(n-12) -50*a(n-13) -12*a(n-14) +12*a(n-15) for n>16

Example

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

Crossrefs

Cf. A317376.

Sequence in context: A050529 A215613 A306138 * A244632 A042030 A042032

Adjacent sequences: A317368 A317369 A317370 * A317372 A317373 A317374

Keyword

nonn

Author

R. H. Hardin, Jul 26 2018

Status

approved