OFFSET
1,1
COMMENTS
Column 3 of A232948
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 13*a(n-1) -15*a(n-2) +9*a(n-3) -2*a(n-4) for n>5.
Empirical: g.f. 9*x -x*(-99+124*x-73*x^2+16*x^3) / ( 1-13*x+15*x^2-9*x^3+2*x^4 ). - R. J. Mathar, Nov 27 2015
EXAMPLE
Some solutions for n=5
..0..0..1....0..2..3....0..2..0....0..2..3....0..0..0....0..2..0....0..2..2
..0..0..0....2..2..3....2..2..2....0..2..3....0..1..1....0..2..2....0..2..2
..1..1..1....2..2..3....2..2..2....0..2..3....1..0..0....0..0..2....0..0..2
..1..0..1....2..2..3....3..3..3....2..3..2....0..2..2....0..2..2....1..0..0
..1..1..3....3..3..1....2..3..2....2..2..2....2..3..2....2..3..3....0..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 02 2013
STATUS
approved