OFFSET
1,1
COMMENTS
Column 2 of A204740
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) -2*a(n-2) -8*a(n-3) +11*a(n-4) -4*a(n-5).
Empirical G.f.: x*(15-17*x-27*x^2+50*x^3-20*x^4)/((1-x)^3*(1-x-4*x^2)). [Colin Barker, Jan 19 2012]
EXAMPLE
Some solutions for n=4
..1..0..1....0..1..1....1..0..1....0..1..1....0..1..1....0..1..0....1..1..0
..1..1..1....1..1..0....1..1..1....1..0..1....1..0..1....1..0..1....0..1..1
..1..1..1....0..1..1....1..0..1....1..1..1....0..1..0....1..1..1....1..0..1
..1..1..1....1..0..1....1..1..0....1..0..1....1..1..1....1..0..1....1..1..0
..1..1..1....1..1..0....1..0..1....0..1..1....1..0..1....1..1..1....0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 18 2012
STATUS
approved