OFFSET
1,1
COMMENTS
Column 1 of A206366.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 16*a(n-1) - 42*a(n-2) + 234*a(n-3) - 784*a(n-4) + 714*a(n-5) - 609*a(n-6) + 1008*a(n-7) for n>8.
Empirical g.f.: x*(15 - 89*x + 204*x^2 - 1460*x^3 + 2259*x^4 - 1335*x^5 + 2289*x^6 - 1008*x^7) / ((1 - 2*x - 3*x^3)*(1 - 14*x + 14*x^2 - 203*x^3 + 336*x^4)). - Colin Barker, Jun 15 2018
EXAMPLE
Some solutions for n=4:
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0
..0..1....1..1....0..1....0..1....1..0....1..1....0..1....1..1....1..1....0..1
..1..0....0..0....1..2....2..3....0..1....0..0....1..0....2..0....1..0....1..0
..1..0....1..0....0..2....0..1....1..0....0..1....1..1....1..0....0..2....1..0
..2..1....0..1....2..1....3..1....2..2....1..2....2..2....0..1....3..3....0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 06 2012
STATUS
approved