OFFSET
1,2
COMMENTS
Column 3 of A229672
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 21*a(n-1) -171*a(n-2) +679*a(n-3) -1368*a(n-4) +1344*a(n-5) -512*a(n-6) for n>7.
Empirical: G.f. x -x^2*(-61-274*x+2419*x^2-3156*x^3-1744*x^4+3392*x^5) / (8*x^2-7*x+1)^3. - R. J. Mathar, Sep 29 2013
EXAMPLE
Some solutions for n=3
..0..1..0....0..1..1....0..1..0....0..1..0....0..1..2....0..0..1....0..1..2
..2..3..2....2..3..2....2..3..2....0..2..1....3..1..1....1..2..2....0..0..3
..3..2..0....1..1..0....2..0..2....1..3..1....0..2..3....3..0..3....2..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 27 2013
STATUS
approved