OFFSET
1,3
COMMENTS
Row 2 of A221890.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..162
FORMULA
Empirical: a(n) = 5*a(n-1) -2*a(n-2) +5*a(n-3) -3*a(n-4).
Empirical g.f.: x^3*(8 - 3*x) / (1 - 5*x + 2*x^2 - 5*x^3 + 3*x^4). - Colin Barker, Feb 12 2018
EXAMPLE
Some solutions for n=4:
..0..2..0..1....0..2..1..1....0..1..1..0....0..2..3..1....1..2..0..0
..1..1..3..0....1..1..2..0....1..3..2..0....0..1..1..0....0..1..3..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 30 2013
STATUS
approved