OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (11/120)*n^5 - (1/8)*n^4 + (9/8)*n^3 - (7/8)*n^2 + (287/60)*n - 1.
Conjectures from Colin Barker, Sep 05 2018: (Start)
G.f.: x*(4 - 9*x + 18*x^2 - 5*x^3 + 2*x^4 + x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
EXAMPLE
Some solutions for n=3:
..0..1....1..1....0..0....0..0....1..1....0..1....0..0....0..1....1..1....0..1
..0..0....1..1....1..1....0..1....1..0....0..1....0..1....0..1....0..0....0..1
..1..1....0..1....0..0....1..1....1..0....0..1....0..0....1..0....1..1....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 22 2013
STATUS
approved