OFFSET
1,1
COMMENTS
Column 2 of A231382.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 2*a(n-3) - 2*a(n-4) - a(n-5) for n>6.
Empirical g.f.: x*(2 + 4*x - 5*x^2 + x^3 - 5*x^4 - 2*x^5) / (1 - 3*x + 2*x^2 - 2*x^3 + 2*x^4 + x^5). - Colin Barker, Mar 18 2018
EXAMPLE
Some solutions for n=3:
..1..0....0..1....0..0....1..0....0..0....1..0....0..0....0..1....0..0....0..0
..1..0....0..0....1..1....0..0....0..0....1..0....0..1....0..1....0..0....1..1
..0..0....0..0....1..1....0..0....0..0....1..0....0..1....0..1....1..1....0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2013
STATUS
approved