OFFSET
1,1
COMMENTS
Column 1 of A206635.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 8*a(n-1) + 8*a(n-2) + 6*a(n-3) for n>4.
Empirical g.f.: x*(14 + 9*x + 5*x^2 - 3*x^3) / (1 - 8*x - 8*x^2 - 6*x^3). - Colin Barker, Mar 04 2018
EXAMPLE
Some solutions for n=4:
..0..1....0..1....0..0....0..1....0..1....0..0....0..0....0..1....0..1....0..1
..0..2....0..0....1..1....2..0....2..0....0..0....0..1....1..1....0..2....0..2
..2..0....1..1....1..1....1..2....0..1....0..1....2..1....0..1....1..2....1..1
..0..2....1..0....1..0....2..0....2..2....0..1....2..0....2..2....2..1....1..2
..1..0....2..1....1..2....0..1....2..1....1..2....0..1....1..2....1..0....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 10 2012
STATUS
approved