OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 21*a(n-2) - a(n-3) - 67*a(n-4) - 10*a(n-5) + 46*a(n-6).
Empirical g.f.: 2*x*(44 + 183*x - 123*x^2 - 713*x^3 - 49*x^4 + 513*x^5) / (1 - x - 21*x^2 + x^3 + 67*x^4 + 10*x^5 - 46*x^6). - Colin Barker, Oct 16 2018
EXAMPLE
Some solutions for n=5:
..1..3....1..2....1..1....1..3....2..0....4..4....4..4....2..2....3..2....0..2
..2..2....1..0....2..3....2..3....2..1....2..3....3..2....4..3....3..4....0..1
..0..1....2..3....2..1....1..0....2..3....2..4....1..1....1..2....2..1....2..2
..2..1....1..0....0..0....1..2....4..3....2..3....2..0....1..3....0..1....1..3
..3..4....2..2....2..1....0..0....1..2....2..1....1..1....1..2....0..2....2..3
..2..2....1..0....3..0....1..2....3..3....3..4....2..0....0..2....1..2....4..4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 30 2013
STATUS
approved