OFFSET
1,2
COMMENTS
Column 3 of A229510
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 12*a(n-1) - 36*a(n-2) for n>3.
Conjectures from Colin Barker, Jun 16 2017: (Start)
G.f.: 48*x^2*(1 - 2*x) / (1 - 6*x)^2.
a(n) = 2^(2+n)*3^(n-2)*(2*n - 1) for n>1.
(End)
EXAMPLE
Some solutions for n=4
..0..0..1....0..1..2....0..1..1....0..1..0....0..1..2....0..1..0....0..1..0
..2..2..2....2..1..2....2..2..0....0..2..0....0..1..0....2..2..2....2..1..2
..0..1..1....0..1..0....0..1..1....1..1..0....1..1..2....1..0..0....1..0..2
..1..2..0....1..2..2....2..2..1....0..2..1....0..0..2....1..2..0....2..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 2013
STATUS
approved