OFFSET
1,1
COMMENTS
Column 2 of A188508.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n)=3*a(n-1)-a(n-2)+3*a(n-3)+3*a(n-4)-a(n-5)-a(n-6).
Empirical g.f.: x*(4 + 4*x + 5*x^2 + x^3 - 2*x^4 - x^5) / ((1 - x + 2*x^2 - x^3)*(1 - 2*x - 3*x^2 - x^3)). - Colin Barker, Feb 18 2018
EXAMPLE
Some solutions for 3 X 2:
..1..1....0..1....1..1....1..1....0..1....1..0....0..1....1..1....1..1....0..1
..1..0....1..0....1..1....0..0....0..1....1..0....0..0....0..1....0..1....0..0
..1..0....1..0....1..0....1..0....1..1....0..1....1..1....1..1....1..0....1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 02 2011
STATUS
approved