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%I #10 Mar 13 2017 05:18:40
%S 1,1,1,1,1,2,2,4,4,7,7,14,16,32,46,90,140,258,416,746,1245,2228,3845,
%T 6929,12194,21990,39113,70544,126293,228168,410887,744377,1346837,
%U 2446229,4441502,8084433,14717678,26841848,48977823,89494630,163634188,299532409
%N Number of n-bead necklaces labeled with numbers -1..1 allowing reversal, with sum zero and first and second differences in -1..1.
%H Andrew Howroyd, <a href="/A208963/b208963.txt">Table of n, a(n) for n = 1..100</a>
%e All solutions for n=8:
%e .-1...-1....0...-1
%e .-1...-1....0...-1
%e ..0....0....0...-1
%e ..0....0....0....0
%e ..1....0....0....1
%e ..1....1....0....1
%e ..0....1....0....1
%e ..0....0....0....0
%Y Column 1 of A208970.
%K nonn
%O 1,6
%A _R. H. Hardin_, Mar 03 2012
%E a(34)-a(42) from _Andrew Howroyd_, Mar 12 2017
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