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A087023
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Maximal exponent in prime factorization of n-th cyclic number.
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0
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3, 2, 4, 2, 2, 2, 2, 3, 3, 5, 2, 2, 2, 2, 2, 4, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 5, 2, 2, 2, 5, 2, 7, 2, 3, 2, 2, 5, 3, 4, 2, 3
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| A004042(n) factorized with Dario Alpern's ECM.
Extended using factors of 10^(A001913(n)-1)-1, see Kamada link.
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LINKS
| Dario A. Alpern, Factorization using the Elliptic Curve Method.
Makoto Kamada, Factorizations of 11...11 (Repunit)
Eric Weisstein's World of Mathematics, Cyclic Number
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FORMULA
| a(n) = A051903(A004042(n+1)).
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EXAMPLE
| A004042(2) = 142857 = 37*13*11*3^3, therefore a(1) = 3.
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CROSSREFS
| Cf. A001913, A087020-A087026.
Sequence in context: A139583 A073314 A144808 * A089214 A057038 A175798
Adjacent sequences: A087020 A087021 A087022 * A087024 A087025 A087026
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KEYWORD
| nonn,more,hard
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 30 2003
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EXTENSIONS
| a(12)-a(42) from Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 16 2011
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