OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) - 11*a(n-3) + 4*a(n-4).
Empirical g.f.: 2*x*(3 - 8*x^2 + 3*x^3) / (1 - 6*x + 11*x^3 - 4*x^4). - Colin Barker, Oct 03 2018
EXAMPLE
Some solutions for n=6:
..0..1..2..0..2..1..0....0..1..0..1..2..0..1....0..1..2..2..0..1..0
..2..1..1..2..1..2..1....2..0..1..0..1..0..1....2..0..0..1..2..2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 19 2013
STATUS
approved