OFFSET
1,3
COMMENTS
Column 2 of A195962.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = a(n-1) +3*a(n-3) -a(n-4) -2*a(n-6).
Empirical g.f.: x*(1 + 5*x^2 - 4*x^3 - 2*x^4 - 8*x^5) / ((1 - x)*(1 + x + x^2)*(1 - x - 2*x^3)). - Colin Barker, May 08 2018
EXAMPLE
All solutions for n=5:
..2..1....1..2....2..1....0..0....1..2
..3..1....1..3....1..1....0..0....1..1
..1..1....1..1....1..3....0..0....3..1
..1..3....3..1....1..1....0..0....1..1
..1..2....2..1....2..1....0..0....1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 2011
STATUS
approved