OFFSET
1,1
COMMENTS
Column 4 of A222340.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..109
FORMULA
Empirical: a(n) = 873*a(n-1) - 38091*a(n-2) + 387974*a(n-3).
Empirical g.f.: 6*x*(36 - 1637*x + 16884*x^2) / (1 - 873*x + 38091*x^2 - 387974*x^3). - Colin Barker, Mar 15 2018
EXAMPLE
Some solutions for n=3:
..0..0..2..0....0..2..2..0....0..2..0..0....0..2..0..0....0..2..2..0
..0..3..5..0....0..3..3..0....0..5..3..0....0..0..2..0....0..3..4..0
..0..3..1..1....2..3..3..5....3..3..4..4....3..5..6..3....0..3..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 15 2013
STATUS
approved