OFFSET
1,1
COMMENTS
Column 1 of A200579.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + a(n-2) + a(n-3) - 3*a(n-4) - 2*a(n-5).
Empirical g.f.: 2*x*(1 + x)^2*(1 - x - x^2) / (1 - 2*x - x^2 - x^3 + 3*x^4 + 2*x^5). - Colin Barker, Mar 02 2018
EXAMPLE
Some solutions for n=5:
..2....2....0....2....1....0....0....1....0....0....1....0....2....0....2....0
..1....2....0....2....0....0....1....0....0....0....0....0....2....0....2....1
..1....0....2....1....1....1....0....0....0....0....0....2....1....1....1....0
..0....0....2....1....1....1....0....2....0....2....0....2....1....0....2....0
..1....0....1....0....2....0....1....2....1....2....1....2....2....0....2....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 19 2011
STATUS
approved