OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 7*a(n-3) + a(n-4) + a(n-5) - 7*a(n-6) - 4*a(n-7) + 3*a(n-9) for n>12.
Empirical g.f.: x*(46 + 39*x + 145*x^2 - 27*x^3 - 16*x^4 - 165*x^5 - 43*x^6 + 16*x^7 + 41*x^8 - 19*x^9 + 12*x^10 + 4*x^11) / ((1 + x^2 - x^3)*(1 - x - x^2 - 5*x^3 - x^4 + 3*x^5 + 3*x^6)). - Colin Barker, Dec 28 2018
EXAMPLE
Some solutions for n=4:
..0..0..0..0....0..0..0..0....0..0..1..0....1..1..0..1....1..0..1..0
..0..0..0..0....1..0..0..1....0..0..0..0....0..0..0..1....0..0..1..0
..0..1..0..0....0..0..0..0....0..0..0..0....1..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..1....0..0..0..0
..0..1..0..0....0..0..0..1....1..0..0..0....1..0..0..0....0..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 22 2015
STATUS
approved