OFFSET
1,2
COMMENTS
Row 2 of A229694
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) -27*a(n-2) +27*a(n-3) for n>6.
Empirical: G.f. 3*x^2+43*x^3 -x^4*(245-1034*x+1153*x^2) / (3*x-1)^3. - R. J. Mathar, Sep 29 2013
EXAMPLE
Some solutions for n=3
..0..1..1....0..1..1....0..1..2....0..1..0....0..0..1....0..1..0....0..0..1
..0..0..1....0..0..2....1..1..0....1..0..1....1..2..2....2..0..0....2..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 27 2013
STATUS
approved