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 A208821 Number of n-bead necklaces labeled with numbers -4..4 allowing reversal, with sum zero. 0
 1, 5, 13, 75, 415, 2821, 19657, 144871, 1090645, 8392423, 65527045, 518173267, 4139803293, 33366946637 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 4 of A208825. LINKS Table of n, a(n) for n=1..14. EXAMPLE All solutions for n=3: .-2...-1....0...-4...-2...-3...-3...-3...-1...-4...-2...-2...-4 .-1....0....0....1....0....0...-1....1...-1....0...-2....1....2 ..3....1....0....3....2....3....4....2....2....4....4....1....2 CROSSREFS Sequence in context: A303962 A304927 A163732 * A293259 A064169 A294208 Adjacent sequences: A208818 A208819 A208820 * A208822 A208823 A208824 KEYWORD nonn AUTHOR R. H. Hardin, Mar 01 2012 STATUS approved

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Last modified April 17 01:14 EDT 2024. Contains 371756 sequences. (Running on oeis4.)