A316871 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero.

4, 23, 99, 425, 1877, 8333, 36900, 163433, 724406, 3210961, 14232174, 63085590, 279639102, 1239553378, 5494572826, 24355881186, 107962769031, 478568720832, 2121361756337, 9403406620066, 41682688016275, 184767777113249

Offset

1,1

Comments

Column 3 of A316876.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -a(n-2) +2*a(n-3) -36*a(n-4) -22*a(n-5) +16*a(n-6) +131*a(n-7) +27*a(n-8) -72*a(n-9) -71*a(n-10) +21*a(n-11) +16*a(n-12) -15*a(n-13) -10*a(n-14) -18*a(n-15) -8*a(n-16) for n>17

Example

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

Crossrefs

Cf. A316876.

Sequence in context: A305588 A317006 A227260 * A197854 A317599 A122738

Adjacent sequences: A316868 A316869 A316870 * A316872 A316873 A316874

Keyword

nonn

Author

R. H. Hardin, Jul 15 2018

Status

approved