OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) - 6*a(n-2) - 16*a(n-3) + 12*a(n-4) + 24*a(n-5) + 8*a(n-6).
Empirical g.f.: 2*x^2*(1 - x)*(3 + 5*x - 36*x^2 + 10*x^3) / (1 - 2*x - 2*x^2)^3. - Colin Barker, Sep 20 2018
EXAMPLE
Some solutions for n=3:
..0..1..2....0..1..2....0..1..2....0..1..2....0..0..0....0..0..1....0..1..0
..0..1..1....2..0..0....2..0..1....1..1..2....1..2..1....1..0..1....1..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 27 2013
STATUS
approved