A304546 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.

1, 8, 13, 60, 217, 749, 2822, 10516, 38934, 145185, 542474, 2025645, 7568821, 28294956, 105785530, 395536988, 1479072597, 5531090102, 20684425965, 77354433339, 289289280136, 1081888995062, 4046087436916, 15131752735177

Offset

1,2

Comments

Column 3 of A304551.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -3*a(n-2) -a(n-3) -18*a(n-4) -24*a(n-5) +44*a(n-6) +42*a(n-7) +52*a(n-8) +31*a(n-9) -132*a(n-10) -80*a(n-11) +48*a(n-12) -31*a(n-13) +13*a(n-14) +17*a(n-15) -82*a(n-16) -39*a(n-17) -2*a(n-19) -a(n-20) for n>21

Example

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

Crossrefs

Cf. A304551.

Sequence in context: A359553 A081966 A316527 * A377561 A166670 A107764

Adjacent sequences: A304543 A304544 A304545 * A304547 A304548 A304549

Keyword

nonn

Author

R. H. Hardin, May 14 2018

Status

approved