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Number of n-bead necklaces labeled with numbers -5..5 not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
0

%I #6 Mar 12 2017 23:54:13

%S 1,6,29,221,1683,14037,121117,1079992,9849223,91488850,862442967,

%T 8230097726,79348933361

%N Number of n-bead necklaces labeled with numbers -5..5 not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.

%C Column 5 of A209115.

%e Some solutions for n=6:

%e .-5...-4...-4...-5...-4...-4...-5...-2...-4...-4...-4...-4...-3...-3...-4...-5

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

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 05 2012