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A056301
Number of primitive (period n) n-bead necklace structures using a maximum of five different colored beads.
4
1, 1, 2, 5, 11, 38, 122, 496, 2005, 8707, 38364, 173562, 792827, 3662800, 17034367, 79702578, 374624253, 1767881397, 8370666416, 39751064122, 189262621739, 903220020390, 4319518316898, 20697040024784
OFFSET
1,3
COMMENTS
Turning over the necklace is not allowed. Colors may be permuted without changing the necklace structure.
REFERENCES
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]
FORMULA
a(n) = Sum_{d|n} mu(d) * A056293(n/d); mu = A008683.
CROSSREFS
Sequence in context: A131581 A195985 A367969 * A001344 A056302 A276547
KEYWORD
nonn
STATUS
approved