OFFSET
1,1
COMMENTS
Row 5 of A252305
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>21
EXAMPLE
Some solutions for n=4
..3..1..2..3..1..2....3..3..0..0..0..0....3..3..0..3..0..0....1..0..2..1..0..2
..0..0..0..3..0..3....3..2..1..3..2..1....0..2..1..3..2..1....1..2..3..1..2..3
..2..1..0..2..1..0....2..3..1..2..3..1....2..0..1..2..3..1....0..0..3..0..0..0
..3..1..2..0..1..2....0..0..0..0..3..0....3..0..0..0..0..0....1..0..2..1..3..2
..3..0..3..3..0..3....3..2..1..0..2..1....3..2..1..3..2..1....1..2..3..1..2..0
..2..1..0..2..1..3....2..3..1..2..0..1....2..3..1..2..0..1....0..0..0..0..3..0
..0..1..2..0..1..2....0..3..0..3..3..0....0..0..0..3..0..0....1..3..2..1..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 16 2014
STATUS
approved