OFFSET
1,1
COMMENTS
Column 2 of A206072.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) - 8*a(n-2) for n>6.
Empirical g.f.: 6*x*(25 - 74*x + 48*x^2 + 12*x^3 + 16*x^4 + 16*x^5) / (1 - 7*x + 8*x^2). - Colin Barker, Jun 13 2018
EXAMPLE
Some solutions for n=4:
..1..0..0....0..0..1....2..1..0....1..2..0....0..1..0....0..1..2....2..0..0
..0..2..1....2..1..2....0..2..1....1..0..2....0..2..1....2..1..1....1..2..1
..1..0..2....0..2..0....1..0..2....0..1..0....1..0..2....1..0..2....2..1..2
..2..1..0....1..0..2....2..1..0....1..2..1....0..2..0....2..1..0....1..0..2
..1..0..1....2..1..0....0..2..1....0..0..2....1..0..1....0..2..1....2..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 03 2012
STATUS
approved