OFFSET
1,1
COMMENTS
Column 2 of A206863.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 8*a(n-1) -5*a(n-2) +18*a(n-3) +7*a(n-4) -2*a(n-5) -a(n-6).
Empirical g.f.: x*(9 + 9*x + 22*x^2 + 4*x^3 - 3*x^4 - x^5) / ((1 - x + 3*x^2 - x^3)*(1 - 7*x - 5*x^2 - x^3)). - Colin Barker, Feb 20 2018
EXAMPLE
Some solutions for n=4:
..1..0....0..2....0..2....0..1....2..0....0..2....0..2....2..1....0..2....2..1
..1..1....2..2....0..0....2..1....1..2....0..2....1..1....2..1....0..1....0..2
..0..1....0..0....0..1....2..0....0..2....2..2....2..0....2..2....2..0....1..2
..2..0....2..1....2..1....0..1....2..0....0..2....0..1....1..2....1..0....2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2012
STATUS
approved