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*(595 + 337*x + 341*x^2 - 3108*x^3 - 1316*x^4 - 1046*x^5 + 3456*x^6 + 880*x^7 + 208*x^8 + 128*x^9) / ((1 - 2*x^3)*(1 - 4*x^3)). - Colin Barker, Dec 04 2018
EXAMPLE
Some solutions for n=4:
..1..2..3..2..2..3....1..3..3..0..0..3....3..3..0..0..2..0....3..3..0..3..0..0
..3..2..2..3..2..2....2..3..2..2..3..2....0..0..2..0..0..2....3..2..2..3..2..2
..0..0..3..3..1..3....2..2..3..2..2..3....1..2..3..1..2..3....2..3..2..2..3..2
..2..2..3..2..2..3....0..3..3..1..3..3....0..2..0..0..3..0....0..3..0..3..3..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 18 2014
STATUS
approved