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Search: id:A054720
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| A054720 |
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Number of 5-ary sequences with primitive period n. |
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+0
6
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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
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OFFSET
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0,2
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COMMENT
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Equivalently, output sequences with primitive period n from a simple cycling shift register.
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REFERENCES
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E. N. Gilbert and J. Riordan, Symmetry types of periodic sequences, Illinois J. Math., 5 (1961), 657-665.
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FORMULA
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Sum mu(d)*5^(n/d); d|n.
a(0) = 1, a(n) = n * A001692(n).
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CROSSREFS
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Sequence in context: A020039 A117736 A028944 this_sequence A110373 A081067 A024066
Adjacent sequences: A054717 A054718 A054719 this_sequence A054721 A054722 A054723
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Apr 20 2000
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