OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) for n>6.
Empirical: a(n) = 49*3^(n-1) + 2730*2^(n-1) + 14306 for n>3.
Conjectures from Colin Barker, Dec 16 2018: (Start)
G.f.: x*(19701 - 97231*x + 116576*x^2 - 4302*x^3 - 5844*x^4 - 288*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)).
a(n) = 14306 + 1365*2^n + 49*3^(n-1) for n>3.
(End)
EXAMPLE
Some solutions for n=4:
..0..1..0..1..2..0..0....0..1..0..0..2..1..1....0..2..2..2..1..1..1
..2..1..0..1..2..0..0....2..2..0..0..2..1..1....1..2..2..2..1..1..1
..2..1..0..1..2..0..0....2..2..0..0..2..1..1....1..2..2..2..1..1..1
..2..1..0..1..2..0..0....2..2..0..0..2..1..1....0..1..1..1..0..0..0
..2..1..0..1..2..0..1....2..2..0..0..2..1..2....0..1..1..1..0..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 02 2015
STATUS
approved