OFFSET
1,1
COMMENTS
Column 3 of A204651.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) -5*a(n-2) +5*a(n-4) -4*a(n-5) +a(n-6) for n>7.
Conjectures from Colin Barker, Jun 08 2018: (Start)
G.f.: x*(28 - 56*x + 20*x^2 + 42*x^3 - 48*x^4 + 20*x^5 - 3*x^6) / ((1 - x)^5*(1 + x)).
a(n) = (256 + 400*n + 144*n^2 + 16*n^3 + 2*n^4)/32 for n>1 and even.
a(n) = (238 + 400*n + 144*n^2 + 16*n^3 + 2*n^4)/32 for n>1 and odd.
(End)
EXAMPLE
Some solutions for n=5:
..0..0..0..1....0..0..0..1....0..0..0..0....0..0..0..0....0..0..0..0
..1..1..1..1....0..0..0..1....0..0..1..1....0..0..0..1....0..0..0..0
..1..1..1..1....0..0..0..1....1..1..1..1....0..0..0..1....0..0..0..0
..1..1..1..1....0..0..1..1....1..1..1..1....0..0..0..1....0..0..0..1
..1..1..1..1....0..1..1..1....1..1..1..1....0..0..1..1....0..0..0..1
..1..1..1..1....1..1..1..1....1..1..1..1....0..0..1..1....1..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2012
STATUS
approved