OFFSET
1,1
COMMENTS
Column 2 of A224606
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) -2*a(n-2) -a(n-3) +a(n-4) -a(n-5) +2*a(n-6) -a(n-7) for n>9.
Empirical g.f.: 178*x + 272*x^2 -x^3*(-371 +664*x -25*x^2 -273*x^3 +123*x^4 -384*x^5 +268*x^6) / ( (1+x)*(x^3+x-1)*(x-1)^3 ). - R. J. Mathar, Aug 22 2016
EXAMPLE
Some solutions for n=3
..1..0..0..0....1..0..0..0....1..0..0..2....1..1..1..1....1..1..2..1
..1..0..0..0....1..0..0..0....1..0..0..2....0..0..0..0....0..0..0..0
..1..0..0..0....1..0..0..0....1..0..0..1....0..0..0..0....0..0..0..0
..0..0..0..1....0..0..0..0....2..0..0..1....1..1..1..1....0..0..0..0
..1..0..0..1....2..0..0..0....1..0..0..1....0..0..0..0....2..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Apr 11 2013
STATUS
approved