OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 21*a(n-1) - 112*a(n-2) + 217*a(n-3) - 157*a(n-4) + 36*a(n-5) for n>6.
Empirical g.f.: x*(8 - 49*x + 109*x^2 - 114*x^3 + 218*x^4 - 78*x^5) / (1 - 21*x + 112*x^2 - 217*x^3 + 157*x^4 - 36*x^5). - Colin Barker, Sep 12 2018
EXAMPLE
Some solutions for n=4:
..1..0..1..0..0..0....1..0..1..0..0..0....1..0..0..1..0..1....1..0..0..0..0..1
..1..0..1..0..0..1....0..0..0..0..1..0....1..0..0..0..0..1....1..0..0..0..0..1
..0..0..1..0..0..1....0..0..1..0..1..0....0..0..0..0..0..1....1..0..0..0..0..0
..0..0..0..1..0..0....1..0..1..0..0..1....0..1..0..1..0..1....0..1..0..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 02 2013
STATUS
approved