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A056353
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Number of bracelet structures using a maximum of three different colored beads.
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11
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1, 1, 2, 3, 6, 9, 22, 40, 100, 225, 582, 1464, 3960, 10585, 29252, 80819, 226530, 636321, 1800562, 5107480, 14548946, 41538916, 118929384, 341187048, 980842804, 2824561089, 8147557742, 23536592235, 68087343148, 197216119545, 571924754778, 1660419530056, 4825588205920
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OFFSET
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0,3
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COMMENTS
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Turning over will not create a new bracelet. Permuting the colors of the beads will not change the structure.
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REFERENCES
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M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]
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LINKS
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FORMULA
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Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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a(0)=1 prepended and terms a(28) and beyond from Andrew Howroyd, Oct 25 2019
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STATUS
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approved
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