OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 64*a(n-1) - 960*a(n-2) + 4096*a(n-3) for n>4.
Empirical g.f.: x*(3 - 156*x + 2016*x^2 - 7168*x^3) / ((1 - 8*x)*(1 - 56*x + 512*x^2)). - Colin Barker, Oct 10 2018
EXAMPLE
Some solutions for n=4:
..0..1..7....0..1..2....0..1..0....0..1..2....0..1..2....0..1..2....0..1..2
..2..3..1....3..0..1....2..3..1....3..7..6....5..7..6....3..7..1....5..3..7
..7..2..0....2..3..7....6..0..5....1..5..4....6..5..3....2..4..2....0..5..1
..3..6..2....7..5..1....3..6..0....4..6..5....0..1..0....7..1..7....3..7..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 05 2013
STATUS
approved