OFFSET
1,1
COMMENTS
Column 2 of A209814.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 17*a(n-1) - 68*a(n-2) - 56*a(n-3) + 397*a(n-4) - 181*a(n-5) - 264*a(n-6) + 108*a(n-7).
Empirical g.f.: x*(34 - 276*x - 101*x^2 + 1688*x^3 - 935*x^4 - 1182*x^5 + 504*x^6) / ((1 - 6*x - 3*x^2 + 2*x^3)*(1 - 11*x + 5*x^2 + 51*x^3 - 54*x^4)). - Colin Barker, Jul 13 2018
EXAMPLE
Some solutions for n=4:
..0..0..0....0..0..1....0..0..0....0..1..1....0..0..0....0..1..1....0..1..0
..1..1..1....1..0..0....0..1..0....0..0..1....0..1..1....0..0..0....0..1..0
..0..0..0....1..0..1....0..1..0....1..1..0....1..0..1....0..1..1....0..1..0
..1..0..1....0..0..0....1..1..0....0..0..0....1..0..0....1..1..2....1..0..0
..0..0..0....0..1..1....2..1..0....0..1..0....1..0..1....1..2..1....0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 13 2012
STATUS
approved