OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) + 6*a(n-2) - 50*a(n-3) + 16*a(n-4) + 80*a(n-5) - 16*a(n-6).
Empirical g.f.: 2*x*(28 - 47*x - 331*x^2 + 364*x^3 + 712*x^4 - 152*x^5) / ((1 - 2*x)*(1 - 2*x - 4*x^2)*(1 - x - 10*x^2 + 2*x^3)). - Colin Barker, Oct 12 2018
EXAMPLE
Some solutions for n=5:
..0..1....4..2....4..1....0..4....4..0....0..2....4..0....3..0....0..4....3..4
..1..4....2..0....4..1....4..4....2..2....4..2....4..4....3..0....1..1....3..0
..0..1....4..2....4..1....0..4....4..0....0..2....1..1....3..0....4..4....3..0
..4..1....2..0....1..4....4..4....1..1....4..2....4..0....0..3....1..1....0..3
..4..1....4..2....1..0....0..4....4..4....2..0....1..1....4..3....4..4....3..4
..0..1....2..0....4..1....2..2....4..0....4..2....4..4....0..3....0..4....0..3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2013
STATUS
approved