OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-3) for n>5.
Empirical g.f.: x*(719 + 462*x + 626*x^2 - 2086*x^3 - 172*x^4) / (1 - 4*x^3). - Colin Barker, Dec 04 2018
EXAMPLE
Some solutions for n=4:
..0..2..0..0..3..0....3..1..3..3..1..3....2..1..0..1..1..0....3..0..3..3..0..3
..1..1..0..1..1..0....2..2..3..2..2..3....2..0..0..3..0..3....2..2..3..2..2..3
..0..1..1..0..1..1....3..2..2..3..2..2....1..0..1..1..0..1....3..2..2..3..2..2
..0..2..0..0..2..0....3..1..3..3..1..3....1..1..0..1..1..0....3..0..3..3..0..3
..1..1..0..1..1..0....2..2..3..2..2..3....3..0..0..3..0..0....2..2..3..2..2..3
..0..1..1..0..1..1....3..2..2..3..1..2....1..0..1..1..0..1....3..2..2..3..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 18 2014
STATUS
approved
