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A056424
Number of primitive (period n) step cyclic shifted sequences using exactly two different symbols.
1
0, 1, 2, 3, 4, 8, 8, 18, 18, 38, 28, 142, 72, 234, 360, 669, 520, 2606, 1608, 7338, 8856, 19370, 16768, 94308, 67556, 216200, 277512, 815310, 662368, 4499852, 2311468, 8465496, 13045076, 31592762, 40937592, 159769394, 103197488, 401912086
OFFSET
1,3
COMMENTS
Identical to A002730 for n>1.
See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent.
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 divides n, mu(d) * A056415(n/d) ).
CROSSREFS
Cf. A002730.
Sequence in context: A080739 A361665 A242065 * A050324 A211227 A019949
KEYWORD
nonn
EXTENSIONS
Added more terms (from A002730), Joerg Arndt, Aug 27 2014
STATUS
approved