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A208800 Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero and three times sum of squares <= n*(3)*(3+1). 1

%I

%S 1,3,5,24,99,518,2782,15485,88835,524548,3150568,19343270,119596665,

%T 746620321,4690323708,29666561267,188933152165,1210058865663,

%U 7790312435430,50365101710864,326846325778607,2128466374313259,13905579793860582,91122902226298461,598778033049098861

%N Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero and three times sum of squares <= n*(3)*(3+1).

%H Andrew Howroyd, <a href="/A208800/b208800.txt">Table of n, a(n) for n = 1..50</a>

%e Some solutions for n=6:

%e .-2...-3...-3...-3...-3...-3...-3...-2...-2...-3...-2...-1...-3...-2...-3...-2

%e ..0....1...-1....0....1....1....0....0...-1...-1....0....0...-1...-1....1...-1

%e ..1...-1....1...-1....1....0....1....2...-1....2....0...-1....1....0...-2....0

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

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

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

%Y Column 3 of A208805.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 01 2012

%E a(17)-a(25) from _Andrew Howroyd_, Mar 02 2017

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Last modified October 1 22:45 EDT 2022. Contains 357173 sequences. (Running on oeis4.)