OFFSET
1,1
COMMENTS
Column 2 of A206267.
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) +3*a(n-4) -a(n-5) for n>6.
Conjectures from Colin Barker, Jun 14 2018: (Start)
G.f.: x*(24 - 44*x + 8*x^2 + 36*x^3 - 27*x^4 + 5*x^5) / ((1 - x)^4*(1 + x)).
a(n) = (72 + 26*n + 9*n^2 + n^3) / 6 for n>1 and even.
a(n) = (78 + 26*n + 9*n^2 + n^3) / 6 for n>1 and odd.
(End)
EXAMPLE
Some solutions for n=4:
..1..1..0....1..0..1....1..0..0....0..1..1....1..0..0....0..0..1....1..1..1
..0..1..1....0..1..0....1..1..0....0..0..1....0..0..0....0..1..0....1..1..1
..0..0..1....1..0..1....0..1..1....1..0..0....0..0..0....1..0..1....1..1..0
..1..0..0....0..1..0....0..0..1....1..1..0....0..0..0....0..1..0....1..0..0
..1..1..0....1..0..1....1..0..0....0..1..1....0..0..0....1..0..1....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 05 2012
STATUS
approved