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A056439
Number of primitive (period n) step cyclic shifted sequence structures using a maximum of two different symbols.
2
1, 1, 1, 2, 2, 5, 4, 10, 9, 22, 14, 78, 36, 124, 180, 343, 260, 1329, 804, 3732, 4428, 9742, 8384, 47364, 33778, 108292, 138756, 408244, 331184, 2251604, 1155734
OFFSET
1,4
COMMENTS
See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. 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. [See A056391 for pdf file of Chap. 2]
FORMULA
Sum mu(d)*A056429(n/d) where d divides n.
CROSSREFS
Cf. A002730.
Sequence in context: A292385 A332895 A095057 * A056444 A319925 A112472
KEYWORD
nonn
STATUS
approved