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>11.
Empirical g.f.: 2*x*(784 + 362*x + 277*x^2 - 4316*x^3 - 1543*x^4 - 845*x^5 + 5182*x^6 + 1091*x^7 + 292*x^8 + 264*x^9 + 484*x^10) / ((1 - 2*x^3)*(1 - 4*x^3)). - Colin Barker, Dec 01 2018
EXAMPLE
Some solutions for n=4:
..0..3..3..1..3....2..0..1..1..0....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....0..2..0..0..2....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....1..0..1..1..0....3..1..3..3..0....1..3..3..0..3
..1..3..3..0..3....1..0..1..1..0....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....0..2..0..0..2....2..3..2..2..3....3..2..2..3..2
..3..2..2..3..2....2..0..1..1..0....3..0..3..3..0....1..3..3..0..3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 14 2014
STATUS
approved