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A056477 Number of primitive (aperiodic) palindromic structures using a maximum of three different symbols. 3
1, 0, 1, 1, 4, 3, 13, 12, 39, 36, 121, 116, 364, 351, 1088, 1080, 3280, 3237, 9841, 9800, 29510, 29403, 88573, 88440, 265716, 265356, 797121, 796796, 2391484, 2390352, 7174453 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Permuting the symbols will not change the structure.

REFERENCES

M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia.

LINKS

Table of n, a(n) for n=1..31.

FORMULA

a(n) = Sum mu(d)*b(n/d) where d|n and b() = 1, 1, 2, 2, 5, 5, 14, 14, 41, 41, 122, 122, ... (A007051 repeated).

CROSSREFS

Cf. A056459.

Sequence in context: A169706 A120340 A082018 * A105200 A088933 A019136

Adjacent sequences:  A056474 A056475 A056476 * A056478 A056479 A056480

KEYWORD

nonn

AUTHOR

Marks R. Nester (nesterm(AT)dpi.qld.gov.au)

STATUS

approved

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Last modified April 17 17:56 EDT 2014. Contains 240655 sequences.