OFFSET
1,2
COMMENTS
Column 4 of A183328.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 2*a(n-3) + 2*a(n-5) - 5*a(n-7) - 3*a(n-8).
Empirical g.f.: x*(1 + x)^2*(1 - x + x^2 + 2*x^3 - 2*x^4 - 3*x^5) / (1 - 3*x + 2*x^2 - 2*x^3 - 2*x^5 + 5*x^7 + 3*x^8). - Colin Barker, Mar 27 2018
EXAMPLE
Some solutions for 8 X 4:
..1..1..1..1....1..1..1..1....0..0..0..0....1..1..1..0....0..1..1..0
..1..0..0..1....1..0..0..1....0..0..0..0....1..0..1..1....0..1..1..0
..1..1..0..1....1..0..1..1....0..0..1..1....1..0..0..1....0..0..0..0
..0..1..0..1....1..0..1..0....0..0..1..1....1..0..0..1....0..1..1..1
..0..1..0..1....1..0..1..1....0..0..0..0....1..0..0..1....0..1..0..1
..0..1..1..1....1..0..0..1....0..0..1..1....1..0..0..1....1..1..0..1
..0..0..0..0....1..0..0..1....0..0..1..1....1..1..1..1....1..0..0..1
..0..0..0..0....1..1..1..1....0..0..0..0....0..0..0..0....1..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 03 2011
STATUS
approved