OFFSET
1,1
COMMENTS
Column 5 of A208314.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 17*a(n-1) - 105*a(n-2) + 354*a(n-3) - 756*a(n-4) + 1062*a(n-5) - 945*a(n-6) + 459*a(n-7) - 81*a(n-8).
Empirical g.f.: 2*x*(8 - 55*x + 186*x^2 - 381*x^3 + 504*x^4 - 405*x^5 + 162*x^6 - 27*x^7) / ((1 - 3*x + 3*x^2)*(1 - 14*x + 60*x^2 - 132*x^3 + 180*x^4 - 126*x^5 + 27*x^6)). - Colin Barker, Jul 02 2018
EXAMPLE
Some solutions for n=4:
..0..0..1..1..1....0..1..1..0..0....0..1..0..0..1....0..0..1..0..0
..0..1..0..0..0....0..1..0..1..0....1..0..1..1..0....1..1..0..1..0
..0..0..1..0..1....1..0..1..0..1....1..1..0..1..1....1..0..1..0..1
..1..1..0..1..0....0..1..0..1..0....1..0..1..0..1....0..1..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 25 2012
STATUS
approved