OFFSET
1,2
COMMENTS
Column 3 of A252876
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/360)*n^6 + (1/20)*n^5 + (5/18)*n^4 + (1/3)*n^3 + (79/360)*n^2 - (113/60)*n + 2.
Empirical: G.f.: -x*(1+x+9*x^2-22*x^3+21*x^4-10*x^5+2*x^6) / (x-1)^7. - R. J. Mathar, Nov 23 2015
EXAMPLE
Some solutions for n=3
..0..1..1....0..1..1....0..1..2....0..0..0....0..1..1....0..0..1....0..1..1
..0..1..1....1..1..1....0..1..2....1..1..1....1..2..2....1..1..1....1..1..1
..1..2..2....1..1..2....1..2..2....1..2..2....2..2..2....1..2..2....2..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 24 2014
STATUS
approved