OFFSET
1,2
COMMENTS
Column 2 of A221676.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) - 9*a(n-2) - 5*a(n-3) + 10*a(n-4) - 3*a(n-5).
Empirical g.f.: x*(1 - x)^2 / (1 - 7*x + 9*x^2 + 5*x^3 - 10*x^4 + 3*x^5). - Colin Barker, Aug 10 2018
EXAMPLE
Some solutions for n=3:
..0..0....1..1....0..2....2..1....2..1....1..1....2..1....0..1....1..0....1..2
..2..1....1..2....1..2....1..1....1..0....1..0....0..0....1..2....2..2....0..1
..2..1....0..1....1..0....0..1....1..1....2..1....1..2....1..1....0..1....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 21 2013
STATUS
approved