OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) - 14*a(n-3) + 10*a(n-4) - 2*a(n-5) for n>6.
Empirical g.f.: 2*x*(4 - 6*x - 11*x^2 + 2*x^3 + 8*x^4 - 3*x^5) / (1 - 9*x + 14*x^3 - 10*x^4 + 2*x^5). - Colin Barker, Jan 30 2019
EXAMPLE
Some solutions for n=4:
..0..1..0..2..0. .0..1..0..1..2. .0..1..0..2..1. .0..1..2..1..2
..2..0..1..0..2. .2..0..2..0..1. .1..0..2..0..2. .1..2..1..0..1
..0..2..0..1..0. .0..2..0..1..0. .0..1..0..2..1. .2..1..2..1..0
..1..0..1..0..2. .2..1..2..0..1. .1..0..2..0..2. .1..0..1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 04 2016
STATUS
approved