A300925 Number of nX3 0..1 arrays with every element equal to 1, 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 11, 75, 508, 3447, 23404, 158855, 1078231, 7318522, 49674630, 337167639, 2288532749, 15533466237, 105433742828, 715633842274, 4857380402810, 32969576037134, 223781720583309, 1518923337407277, 10309725472244584

Offset

1,2

Comments

Column 3 of A300930.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +6*a(n-2) -3*a(n-3) -9*a(n-4) -6*a(n-5) +3*a(n-6) +6*a(n-7) +2*a(n-8) for n>10

Example

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

Crossrefs

Cf. A300930.

Sequence in context: A231917 A289419 A027226 * A347987 A157232 A305661

Adjacent sequences: A300922 A300923 A300924 * A300926 A300927 A300928

Keyword

nonn

Author

R. H. Hardin, Mar 15 2018

Status

approved