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A208799 Number of n-bead necklaces labeled with numbers -2..2 allowing reversal, with sum zero and three times sum of squares <= n*(2)*(2+1). 1
1, 2, 4, 11, 33, 105, 395, 1612, 6323, 27727, 115117, 506417, 2240045, 9863620, 44646673, 200485659, 912889175, 4178508224, 19142413757, 88521250696, 409486689399, 1904094176208, 8884513374761, 41533090926064, 194937511464985 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..100

EXAMPLE

Some solutions for n=6:

.-2...-1...-2...-1...-2...-2...-2...-2...-1...-2...-2...-1...-1...-1...-2...-1

..0....1....1....0....1....0...-1....1....0....0....0...-1....0....0...-1...-1

..1...-1....0...-1...-1....0....1...-1...-1....0....1....0....0...-1....0....0

..0....1....0....0....0....1....2...-1....0....1...-1....1....1....1....2...-1

..1...-1...-1....0....1....1....0....1....2....0....0....0...-1...-1....0....2

..0....1....2....2....1....0....0....2....0....1....2....1....1....2....1....1

CROSSREFS

Column 2 of A208805.

Sequence in context: A035354 A220902 A249945 * A340329 A268323 A268324

Adjacent sequences:  A208796 A208797 A208798 * A208800 A208801 A208802

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 01 2012

EXTENSIONS

a(20)-a(25) from Andrew Howroyd, Mar 02 2017

STATUS

approved

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Last modified August 17 08:02 EDT 2022. Contains 356184 sequences. (Running on oeis4.)