A305335 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 5 or 8 king-move adjacent elements, with upper left element zero.

4, 5, 12, 26, 62, 166, 431, 1091, 2812, 7268, 18741, 48294, 124560, 321313, 828693, 2137285, 5512541, 14218105, 36671374, 94583059, 243949927, 629198761, 1622836684, 4185639740, 10795653340, 27844280385, 71816305058, 185229485865

Offset

1,1

Comments

Column 3 of A305340.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A305340.

Sequence in context: A352720 A369697 A308775 * A123102 A274077 A028272

Adjacent sequences: A305332 A305333 A305334 * A305336 A305337 A305338

Keyword

nonn

Author

R. H. Hardin, May 30 2018

Status

approved