OFFSET
1,1
COMMENTS
Column 1 of A184231.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Conjectures: a(n) = 3*a(n-1)+3*a(n-2)-6*a(n-3); G.f.: -3*x*(2*x+1)*(6*x-5) / (6*x^3-3*x^2-3*x+1). - Colin Barker, Sep 26 2014
EXAMPLE
Some solutions for 3X2
..3..2....2..0....3..2....3..0....2..3....0..2....0..3....3..0....2..0....0..3
..0..3....0..2....0..3....0..2....3..0....3..0....3..0....0..3....1..3....3..0
..2..1....3..1....3..0....2..0....0..3....0..2....0..1....3..2....3..1....1..3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 10 2011
STATUS
approved