OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..149
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) + 5322*2^(n-1) + 38777 for n>3.
Empirical g.f.: x*(48293 - 238591*x + 284807*x^2 - 7761*x^3 - 8714*x^4 - 480*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)). - Colin Barker, Dec 16 2018
EXAMPLE
Some solutions for n=4:
..0..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....0..0..0..1..1..0..0..0
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....2..1..1..2..2..1..1..1
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....2..1..1..2..2..1..1..1
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..1....1..0..0..1..1..0..0..0
..1..1..2..1..0..1..1..1....0..2..1..2..2..1..2..2....1..0..0..1..1..0..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 02 2015
STATUS
approved