OFFSET
1,1
COMMENTS
Column 3 of A183719.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) + 10*a(n-2) - 10*a(n-4) - 2*a(n-5) + a(n-6).
Empirical g.f.: 2*x*(6 + 15*x - 2*x^2 - 19*x^3 - 4*x^4 + 2*x^5) / ((1 - x)*(1 + x)*(1 - 2*x - 9*x^2 - 2*x^3 + x^4)). - Colin Barker, Apr 04 2018
EXAMPLE
Some solutions for 3 X 4:
..0..4..1..4....0..4..0..4....4..0..4..0....3..0..3..4....3..2..3..2
..2..3..2..3....1..2..1..3....3..2..3..2....2..1..2..0....0..1..0..1
..0..4..1..0....0..3..0..4....0..1..4..0....3..4..3..4....3..2..4..2
...
...L..R..L.......L..R..L.......R..L..R.......R..L..R.......L..R..L...
...R..L..R.......R..L..R.......L..R..L.......L..R..L.......R..L..R...
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2011
STATUS
approved