OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-2) - 3*a(n-4) + 4*a(n-6).
Empirical g.f.: 8*x*(19 + 34*x - 6*x^2 - 14*x^3 + 15*x^4 + 48*x^5) / (1 - 4*x^2 + 3*x^4 - 4*x^6). - Colin Barker, Dec 11 2018
EXAMPLE
Some solutions for n=4:
..1..1..1....0..0..1....0..1..1....0..1..1....0..1..1....0..0..0....1..0..1
..1..0..1....1..1..1....0..0..0....1..0..0....0..1..0....1..0..1....1..1..0
..0..1..0....1..0..1....0..1..0....0..0..0....1..1..1....0..1..0....1..0..1
..1..1..1....0..1..1....0..0..0....1..0..1....0..1..1....0..0..0....0..1..1
..0..1..1....1..0..1....0..1..0....0..0..0....1..0..1....0..1..0....1..0..1
..1..0..1....0..1..1....1..0..1....1..0..1....0..1..1....0..0..1....1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 30 2014
STATUS
approved