%I #7 Mar 13 2017 00:02:33
%S 1,3,12,122,1722,33469,817594,24194286,841661871,33691654098
%N Number of n-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2.
%C Diagonal of A209073.
%e Some solutions for n=6:
%e .-6...-4...-6...-6...-5...-6...-6...-6...-6...-6...-6...-5...-3...-5...-3...-6
%e .-1....3...-3....4...-4...-5....1...-1....1...-4...-5....5....0....2...-2...-4
%e ..6....2....3....5....3....2....0....5...-1...-3....4....1....2...-4....1....6
%e .-3...-1...-2...-2....6....5...-1....4....6....3....4....6....1...-2...-2....1
%e ..1....0....2....2....4...-2....6....3....3....4....0...-3....2....3....3....0
%e ..3....0....6...-3...-4....6....0...-5...-3....6....3...-4...-2....6....3....3
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 04 2012
|