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%I #9 Mar 19 2018 04:10:25
%S 39,1007,8008,37108,125428,344618,817594,1738838,3397900,6206228,
%T 10727576,17711618,28130798,43220926,64524812,93939228,133765612,
%U 186763798,256208998,345952710,460486468,605008920,785496844,1008779010
%N Number of 7-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2.
%C Row 7 of A209073.
%H R. H. Hardin, <a href="/A209076/b209076.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) - 11*a(n-2) + 16*a(n-3) - 20*a(n-4) + 22*a(n-5) - 19*a(n-6) + 11*a(n-7) - 11*a(n-9) + 19*a(n-10) - 22*a(n-11) + 20*a(n-12) - 16*a(n-13) + 11*a(n-14) - 5*a(n-15) + a(n-16) for n > 18.
%e Some solutions for n=6:
%e -4 -5 -4 -6 -5 -6 -5 -6 -6 -6 -4 -6 -5 -5 -6 -5
%e -4 -1 -4 -1 -4 -5 -2 -4 -1 -5 -3 -3 -5 -1 -4 -5
%e -2 2 1 2 1 1 2 0 2 5 4 2 6 6 4 -5
%e 6 4 5 6 4 6 3 4 5 6 3 5 3 1 5 4
%e 2 -2 6 -1 3 3 2 5 -4 0 -3 0 -4 -4 1 2
%e -2 -3 -4 5 0 2 2 -2 2 -4 0 2 0 -2 -4 6
%e 4 5 0 -5 1 -1 -2 3 2 4 3 0 5 5 4 3
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 04 2012
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