OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-3) - 8*a(n-6) for n>10.
Empirical g.f.: x*(730 + 337*x + 334*x^2 - 3954*x^3 - 1346*x^4 - 1040*x^5 + 4628*x^6 + 952*x^7 + 224*x^8 + 144*x^9) / ((1 - 2*x^3)*(1 - 4*x^3)). - Colin Barker, Dec 04 2018
EXAMPLE
Some solutions for n=4:
..3..1..2..3....0..2..0..0....1..0..1..1....2..0..0..3....2..3..2..2
..3..1..3..3....1..1..0..1....2..1..0..1....1..0..1..1....1..2..3..2
..2..2..3..2....0..1..1..0....2..0..0..2....1..1..0..1....1..3..3..1
..3..2..2..3....0..2..0..0....1..0..1..1....2..0..0..2....2..3..2..2
..3..0..3..3....1..1..0..1....1..1..0..1....1..0..1..2....2..2..3..1
..2..2..3..2....0..1..1..0....2..0..0..3....1..1..0..1....1..3..3..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 18 2014
STATUS
approved