%I #6 Mar 13 2017 00:09:53
%S 1,2,3,10,31,153,703,3393,16001,75381,357369,1713043,8299559,40613618,
%T 200412275,995895544
%N Number of n-bead necklaces labeled with numbers -4..4 not allowing reversal, with sum zero and first and second differences in -4..4.
%C Column 4 of A209007.
%e Some solutions for n=6:
%e .-1...-3...-2...-2...-2...-1...-3...-3...-1...-2...-2...-2...-3...-2...-2....0
%e ..0...-3....1....0...-2....1...-1...-3....0....1...-1....0...-1...-2....0....0
%e ..1....1....1....0....0...-1....2....1....0....2....1....0....2....0...-1....0
%e .-1....1....0....2....3....1....3....2....1....0....2....1....2....2....2....0
%e ..0....3....1....1....2....0....0....3...-1....0....1....1....2....2....1....0
%e ..1....1...-1...-1...-1....0...-1....0....1...-1...-1....0...-2....0....0....0
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 04 2012