OFFSET
1,1
COMMENTS
Column 2 of A220977.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - 4*a(n-2) + 3*a(n-3) - 5*a(n-4) - 3*a(n-5) + 6*a(n-6) - 8*a(n-7) for n>10.
Empirical g.f.: x*(2 - 6*x + 9*x^2 - 11*x^3 + 6*x^4 - 2*x^5 - 15*x^6 + 21*x^7 - 14*x^8 + 8*x^9) / ((1 + x)*(1 - 2*x)*(1 - 3*x + 3*x^2 - 6*x^3 + 5*x^4 - 4*x^5)). - Colin Barker, Aug 03 2018
EXAMPLE
All solutions for n=3:
..1..1....0..0....0..0....1..1....0..0....1..1....1..1....0..0....1..1
..1..1....1..0....0..1....1..0....0..0....0..0....0..0....0..0....0..1
..1..1....1..1....1..1....0..0....1..1....0..0....1..1....0..0....0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 27 2012
STATUS
approved