id:A056331 - OEIS Search Results

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Number of primitive (aperiodic) reversible string structures with n beads using a maximum of two different colors.

+0
3

1, 1, 2, 4, 9, 16, 35, 66, 133, 261, 527, 1032, 2079, 4123, 8244, 16440, 32895, 65639, 131327, 262380, 524762, 1049071, 2098175, 4195230, 8390646, 16779231, 33558392, 67112892, 134225919, 268443306 (list; graph; listen)

	OFFSET	`1,3`
	COMMENT	`A string and its reverse are considered to be equivalent. Permuting the colors will not change the structure.`
	REFERENCES	`M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia.`
	FORMULA	`sum mu(d)*A005418(n/d) where d divides n.`
	CROSSREFS	`Cf. A045625.` `Sequence in context: A062791 A005980 A128093 this_sequence A056336 A060401 A063981` `Adjacent sequences: A056328 A056329 A056330 this_sequence A056332 A056333 A056334`
	KEYWORD	`nonn`
	AUTHOR	`Marks R. Nester (nesterm(AT)dpi.qld.gov.au)`

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.

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