OFFSET
1,1
COMMENTS
Column 2 of A183474.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) + 4*a(n-3) - 4*a(n-4) - 4*a(n-6).
Empirical g.f.: 2*x*(1 + x - 2*x^3 - 2*x^4 - 2*x^5) / ((1 - 2*x^3)*(1 - 2*x - 2*x^3)). - Colin Barker, Mar 29 2018
EXAMPLE
Some solutions for 4 X 2:
..0..0....1..1....0..0....0..0....1..1....1..1....1..1....1..1....1..1....0..0
..0..0....1..0....1..1....0..0....0..0....0..0....1..1....1..1....0..0....1..1
..0..0....0..1....1..1....1..1....1..0....0..0....0..0....1..1....0..0....1..1
..0..0....1..1....0..0....1..1....1..0....1..1....0..0....0..0....0..0....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2011
STATUS
approved