OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 2*a(n-2) + 5*a(n-3) - 2*a(n-5) - 4*a(n-6).
Empirical g.f.: x*(5 + 8*x + 9*x^2 - 4*x^3 - 8*x^4 - 8*x^5) / (1 - x - 2*x^2 - 5*x^3 + 2*x^5 + 4*x^6). - Colin Barker, Oct 01 2018
EXAMPLE
Some solutions for n=7:
..0..1....0..0....1..1....0..0....1..1....1..0....0..1....0..0....0..0....0..0
..0..0....0..1....0..0....0..0....0..0....0..0....0..0....1..0....0..0....0..0
..0..0....0..1....0..0....0..0....0..0....0..0....1..0....0..1....0..1....0..0
..0..0....0..0....1..0....0..0....0..1....0..1....0..0....0..0....0..0....1..0
..0..0....0..1....0..0....1..0....0..1....0..1....1..0....0..0....0..1....0..0
..0..1....0..0....1..0....0..0....0..0....0..0....1..0....1..1....0..1....0..0
..0..0....0..0....0..0....0..1....0..0....1..0....0..0....0..0....0..0....0..0
..1..0....0..0....1..0....0..0....1..1....0..0....1..0....0..0....0..1....0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 13 2013
STATUS
approved