OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) - 13*a(n-2) + 14*a(n-3) - 10*a(n-4) + 4*a(n-5) - a(n-6).
Empirical g.f.: x*(3 - 9*x + 10*x^2 - 8*x^3 + 3*x^4 - x^5) / (1 - 3*x + 2*x^2 - x^3)^2. - Colin Barker, Jan 13 2019
EXAMPLE
Some solutions for n=9:
..1....0....0....2....2....1....0....2....1....1....2....0....1....0....1....0
..2....0....1....2....2....1....0....2....0....1....0....0....1....2....0....2
..0....2....2....1....2....2....2....1....2....2....2....1....1....2....1....0
..2....1....2....2....2....0....0....0....2....2....2....1....1....2....1....1
..2....1....2....0....2....0....2....1....1....0....2....1....1....2....2....2
..0....1....0....0....0....2....0....1....0....1....2....2....1....2....2....0
..1....0....0....0....0....0....0....1....0....2....0....2....0....1....0....2
..2....1....1....2....0....0....2....2....0....0....0....2....0....0....0....0
..2....2....1....2....0....2....1....0....2....1....1....2....2....0....1....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 04 2016
STATUS
approved