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Number of n-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
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%I #7 Mar 12 2017 23:57:09

%S 1,3,11,120,1683,32802,802125,23766209,827695021,33165786247

%N Number of n-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.

%C Diagonal of A209115.

%e Some solutions for n=6:

%e .-5...-4...-6...-4...-6...-6...-5...-6...-6...-4...-6...-6...-4...-4...-4...-5

%e ..0...-4...-1...-2...-4....0...-1....4....6....5....5....6....0....1...-2...-1

%e .-1....6....6....5....6...-5....6....0...-5...-3....4....2....0....2....3...-2

%e ..5...-1...-6....4....6....6...-2....1...-1....5....1...-2....2....1....1...-4

%e .-3...-1....4....0....2....2....4...-4....5...-3...-5...-2...-1....2....0....6

%e ..4....4....3...-3...-4....3...-2....5....1....0....1....2....3...-2....2....6

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 05 2012