A317735 Number of nX2 0..1 arrays with every element unequal to 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 1, 1, 2, 4, 9, 22, 53, 130, 320, 788, 1942, 4787, 11801, 29093, 71724, 176825, 435937, 1074742, 2649628, 6532293, 16104470, 39703357, 97883170, 241317504, 594935144, 1466730842, 3616023335, 8914808625, 21978235609, 54184319688, 133583994289

Offset

1,4

Comments

Column 2 of A317741.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A317741.

Sequence in context: A055094 A369472 A055729 * A238826 A048211 A098719

Adjacent sequences: A317732 A317733 A317734 * A317736 A317737 A317738

Keyword

nonn

Author

R. H. Hardin, Aug 05 2018

Status

approved