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%I #7 Mar 12 2017 23:56:25
%S 1,2,1,5,5,15,25,68,139,354,813,2047,4935,12421,30833,78102,197139,
%T 503132,1284711,3302155,8503965,21996761,57026957,148322398,386626825,
%U 1010375144,2645762431,6942725217,18251279163,48065184969,126783827201
%N Number of n-bead necklaces labeled with numbers -1..1 not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
%C Column 1 of A209115.
%H R. H. Hardin, <a href="/A209108/b209108.txt">Table of n, a(n) for n = 1..32</a>
%e All solutions for n=6:
%e .-1...-1...-1...-1...-1...-1...-1...-1...-1...-1....0...-1...-1...-1...-1
%e .-1...-1...-1....0....0....1....0....1...-1....1....0...-1....0...-1....0
%e ..1....1....1....0....0...-1...-1....0...-1...-1....0....1....0....0....0
%e ..1....1....0....1....0....1....1....0....1....1....0...-1....1....0...-1
%e ..0...-1....0....0....0...-1....0....0....1....0....0....1...-1....1....1
%e ..0....1....1....0....1....1....1....0....1....0....0....1....1....1....1
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 05 2012
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