OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) - 83*a(n-3) + 15*a(n-4) + 60*a(n-5).
Empirical g.f.: x*(81 - 166*x - 1025*x^2 + 390*x^3 + 840*x^4) / ((1 - x)*(1 - 3*x - 3*x^2)*(1 - 5*x - 20*x^2)). - Colin Barker, Oct 21 2018
EXAMPLE
Some solutions for n=4:
..1..2....0..0....0..0....0..2....0..1....0..2....2..1....2..0....0..1....0..1
..2..0....2..1....1..2....1..1....2..0....0..1....2..2....2..2....2..1....1..0
..2..1....0..0....2..1....0..2....0..2....2..2....2..2....0..1....1..0....1..1
..2..2....1..2....2..0....1..1....0..1....0..0....0..1....1..2....1..2....1..0
..0..0....0..0....2..0....2..2....2..2....1..2....0..2....1..0....0..1....0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 02 2014
STATUS
approved