OFFSET
1,2
COMMENTS
Column 2 of A214166.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 84*a(n-1) - 945*a(n-2) + 1562*a(n-3).
Conjectures from Colin Barker, Jul 22 2018: (Start)
G.f.: x*(1 - 66*x + 335*x^2) / ((1 - 2*x)*(1 - 11*x)*(1 - 71*x)).
a(n) = (781*2^n + 213*11^n + 11*71^n)/4686.
(End)
EXAMPLE
Some solutions for n=4:
..0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2
..1..0..3....1..2..3....2..0..1....1..0..3....2..3..0....2..0..1....2..3..0
..2..3..0....3..4..5....0..2..3....2..3..4....3..2..4....0..1..2....3..4..1
..4..2..3....4..0..1....1..0..4....3..2..5....5..0..2....1..2..3....0..3..4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 05 2012
STATUS
approved