OFFSET
1,1
COMMENTS
Column 2 of A205836.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) -8*a(n-2) +6*a(n-3) for n>4.
Empirical g.f.: 3*x*(37 - 49*x + 40*x^2 + 2*x^3) / (1 - 7*x + 8*x^2 - 6*x^3). - Colin Barker, Jun 13 2018
EXAMPLE
Some solutions for n=4:
..0..1..1....1..2..0....2..1..1....0..0..1....2..1..0....2..1..1....0..2..1
..2..0..2....1..0..1....1..0..2....2..1..2....0..2..1....1..0..2....2..1..2
..2..1..0....2..1..0....2..1..0....0..2..0....1..0..2....2..1..0....0..2..0
..1..0..1....0..2..1....0..2..1....2..1..2....2..1..0....0..2..1....2..0..2
..0..1..2....2..1..2....1..0..2....1..2..1....0..2..1....2..0..2....0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 01 2012
STATUS
approved