A305588 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3, 5 or 6 king-move adjacent elements, with upper left element zero.

4, 23, 95, 390, 1626, 6818, 28530, 119266, 498890, 2087148, 8731184, 36525814, 152804412, 639253506, 2674304822, 11187927898, 46804640008, 195807072344, 819158586242, 3426949449364, 14336642689542, 59977347549018

Offset

1,1

Comments

Column 3 of A305593.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -a(n-2) -3*a(n-3) -29*a(n-4) -14*a(n-5) +22*a(n-6) +95*a(n-7) +40*a(n-8) -70*a(n-9) -84*a(n-10) +13*a(n-11) +57*a(n-12) +4*a(n-13) -28*a(n-14) -26*a(n-15) -8*a(n-16) for n>17

Example

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

Crossrefs

Cf. A305593.

Sequence in context: A317120 A220647 A014585 * A317006 A227260 A316871

Adjacent sequences: A305585 A305586 A305587 * A305589 A305590 A305591

Keyword

nonn

Author

R. H. Hardin, Jun 05 2018

Status

approved