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%I #6 Mar 13 2017 00:17:03
%S 1,2,5,16,59,253,1111,5067,23483,110772,529201,2557073,12471501,
%T 61328336,303723367,1513583006,7584498891,38192683192,193171464383,
%U 980903632155
%N Number of n-bead necklaces labeled with numbers -3..3 not allowing reversal, with sum zero and first differences in -3..3.
%C Column 3 of A208993.
%e Some solutions for n=6:
%e .-1...-1...-3...-2...-1...-3...-2...-2...-2...-2...-2...-2...-2....0...-2...-3
%e .-1...-1....0...-1....0....0....1....1...-2....1....0...-1...-2....0....0....0
%e .-1....0....2....0....0...-1....0...-1....1....1...-1....1....0....0....1....2
%e ..2....0....2....2...-1....2....1...-1....1...-1....2....3....3....0....0....0
%e .-1....0....1....0....0....2...-1....2....1....1....1....0....1....0....0....1
%e ..2....2...-2....1....2....0....1....1....1....0....0...-1....0....0....1....0
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 04 2012
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