OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 8*a(n-1) - 4*a(n-3) + 4*a(n-4) - 12*a(n-5) - 16*a(n-6).
Empirical g.f.: x*(9 - 5*x + 2*x^2 - 4*x^3 - 12*x^4 - 16*x^5) / (1 - 8*x + 4*x^3 - 4*x^4 + 12*x^5 + 16*x^6). - Colin Barker, Sep 27 2018
EXAMPLE
Some solutions for n=5:
..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..0....0..1
..2..2....2..2....2..2....1..0....1..0....2..2....0..1....2..0....1..2....1..2
..0..0....0..0....2..0....2..0....0..0....0..2....0..0....2..0....2..0....1..2
..2..1....2..1....0..2....1..2....2..1....2..0....2..2....0..2....1..0....1..0
..0..0....1..0....2..0....2..2....2..2....0..2....0..0....0..2....0..2....0..1
..2..2....2..2....1..0....1..0....0..0....0..2....1..1....1..0....0..2....2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 05 2013
STATUS
approved