OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 50*a(n-1) - 805*a(n-2) + 4662*a(n-3) - 12150*a(n-4) + 14580*a(n-5) - 6561*a(n-6).
Empirical g.f.: 4*x*(10 - 95*x + 262*x^2 + 93*x^3 - 1485*x^4 + 1701*x^5) / (1 - 25*x + 90*x^2 - 81*x^3)^2. - Colin Barker, Sep 19 2018
EXAMPLE
Some solutions for n=3:
..0..1..2..1..0..1....0..1..0..1..0..1....0..1..2..0..1..2....0..1..2..1..0..1
..0..1..2..0..2..1....2..1..2..1..2..0....2..0..2..0..0..2....2..0..2..1..0..1
..0..1..2..1..0..2....2..1..0..2..1..2....2..0..1..2..1..0....2..0..2..2..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 26 2013
STATUS
approved