

A087022


Total number of prime factors of nth cyclic number.


0



6, 9, 12, 10, 11, 9, 11, 23, 25, 25, 22, 18, 19, 15, 14, 38, 35, 24, 28, 25, 27, 21, 17, 38, 44, 27, 43, 16, 16, 23, 42, 35, 37, 30, 29, 14, 23, 62, 41, 51, 28, 26
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OFFSET

1,1


COMMENTS

A004042(n) factorized with Dario Alpern's ECM.
Extended using factors of 10^(A001913(n)1)1, see Kamada link.


LINKS

Table of n, a(n) for n=1..42.
Dario A. Alpern, Factorization using the Elliptic Curve Method.
Makoto Kamada, Factorizations of 11...11 (Repunit)
Eric Weisstein's World of Mathematics, Cyclic Number


FORMULA

a(n) = A001222(A004042(n+1)).


EXAMPLE

A004042(2) = 142857 = 37*13*11*3^3, therefore a(1) = A087021(1)+2 = 6.


CROSSREFS

Cf. A001913, A087020A087026.
Sequence in context: A125971 A322158 A143710 * A315951 A081392 A225868
Adjacent sequences: A087019 A087020 A087021 * A087023 A087024 A087025


KEYWORD

nonn,more,hard


AUTHOR

Reinhard Zumkeller, Jul 30 2003


EXTENSIONS

a(3) corrected, a(12)a(42) added by Ray Chandler, Nov 16 2011


STATUS

approved



