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A208964 Number of n-bead necklaces labeled with numbers -2..2 allowing reversal, with sum zero and first and second differences in -2..2. 1
1, 1, 1, 3, 3, 8, 15, 42, 94, 246, 613, 1645, 4361, 11980, 33023, 92484, 259762, 735310, 2088403, 5961138, 17070131, 49059542, 141402328, 408736264, 1184435227, 3440434897, 10014880408, 29211476668, 85362417183, 249882401380, 732670159161, 2151506490430 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

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

EXAMPLE

All solutions for n=5:

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

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

..0....0....0

..1....1....0

..0....1....0

CROSSREFS

Column 2 of A208970.

Sequence in context: A055057 A154029 A219349 * A104864 A300367 A296106

Adjacent sequences:  A208961 A208962 A208963 * A208965 A208966 A208967

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 03 2012

EXTENSIONS

a(23)-a(32) from Andrew Howroyd, Mar 12 2017

STATUS

approved

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Last modified December 5 16:12 EST 2019. Contains 329753 sequences. (Running on oeis4.)