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A054720
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Number of 5-ary sequences with primitive period n.
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5
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1, 5, 20, 120, 600, 3120, 15480, 78120, 390000, 1953000, 9762480, 48828120, 244124400, 1220703120, 6103437480, 30517574880, 152587500000, 762939453120, 3814695297000, 19073486328120, 95367421874400, 476837158124880, 2384185742187480
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Equivalently, output sequences with primitive period n from a simple cycling shift register.
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REFERENCES
| E. N. Gilbert and J. Riordan, Symmetry types of periodic sequences, Illinois J. Math., 5 (1961), 657-665.
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FORMULA
| Sum mu(d)*5^(n/d); d|n.
a(0) = 1, a(n) = n * A001692(n).
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CROSSREFS
| Sequence in context: A020039 A117736 A028944 * A110373 A081067 A024066
Adjacent sequences: A054717 A054718 A054719 * A054721 A054722 A054723
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Apr 20 2000
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