%I #6 Mar 13 2017 00:01:33
%S 1,3,6,22,70,265,1007,4055,16593,69429,294509,1265692,5494398,
%T 24065829,106207739,471840078,2108406146,9470071142,42731427358,
%U 193612759011,880517540867
%N Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2.
%C Column 2 of A209073.
%e Some solutions for n=6:
%e .-2...-2...-2...-2...-2...-2...-1...-2...-2...-2...-2...-2...-2...-2...-2...-1
%e ..1...-1....2....1...-1....1...-1...-1....2....0....1....1....0...-2...-1...-1
%e ..2....1....0....0...-1....0....1...-2...-1...-1....1...-1....0...-2....2....0
%e ..0....1...-1....1....2....2...-1....1....2....1....0....1....1....2...-1....0
%e ..0...-1....2...-2....1....0....0....2....0....0...-2....1....1....2....0....0
%e .-1....2...-1....2....1...-1....2....2...-1....2....2....0....0....2....2....2
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 04 2012