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A056304
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Number of primitive (period n) n-bead necklace structures using exactly three different colored beads.
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3
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0, 0, 1, 2, 5, 17, 43, 124, 338, 941, 2591, 7234, 20125, 56407, 158349, 446492, 1262225, 3580330, 10181479, 29031306, 82968799, 237642659, 682014587, 1960974220, 5647919640, 16292741605, 47069104274
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Turning over the necklace is not allowed. Colors may be permuted without changing the necklace structure.
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REFERENCES
| M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia.
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FORMULA
| sum mu(d)*A056296(n/d) where d|n. Alternatively, A002075(n)-A000048(n)..
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CROSSREFS
| Cf. A056288.
Sequence in context: A007351 A076076 A136194 * A063106 A096295 A074494
Adjacent sequences: A056301 A056302 A056303 * A056305 A056306 A056307
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KEYWORD
| nonn
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AUTHOR
| Marks R. Nester (nesterm(AT)dpi.qld.gov.au)
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