OFFSET
1,1
COMMENTS
Column 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
..2..0..1..2..3..1..2....3..2..1..3..2..1..3....0..1..2..0..1..2..3
..0..0..0..0..0..0..3....0..0..0..0..0..3..0....0..0..3..0..0..0..0
..3..2..1..3..2..1..0....1..2..3..1..2..0..1....2..1..3..2..1..3..2
..2..3..1..2..0..1..2....3..2..1..3..2..1..3....0..1..2..3..1..2..0
..0..0..0..3..3..0..3....0..0..0..0..0..3..0....0..0..0..0..0..3..3
..3..2..1..0..2..1..0....1..2..3..1..2..0..1....2..1..3..2..1..3..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 16 2014
STATUS
approved