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A208965 Number of n-bead necklaces labeled with numbers -3..3 allowing reversal, with sum zero and first and second differences in -3..3. 1
1, 1, 2, 4, 9, 29, 87, 325, 1148, 4168, 15250, 57027, 214739, 820038, 3156251, 12243837, 47772129, 187370511, 738088612, 2919087297, 11585698838, 46133010366, 184243108172, 737834327019, 2962231908667, 11920345964795, 48072060624163, 194251242877839 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..50

EXAMPLE

All solutions for n=5:

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

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

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

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

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

CROSSREFS

Column 3 of A208970.

Sequence in context: A005095 A300491 A229686 * A306505 A243789 A214935

Adjacent sequences:  A208962 A208963 A208964 * A208966 A208967 A208968

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 03 2012

EXTENSIONS

a(19)-a(28) from Andrew Howroyd, Mar 12 2017

STATUS

approved

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Last modified November 27 16:20 EST 2021. Contains 349394 sequences. (Running on oeis4.)