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A057954 Number of prime factors of 7^n - 1 (counted with multiplicity). 2
2, 5, 4, 8, 3, 8, 4, 10, 7, 8, 4, 13, 3, 9, 7, 13, 4, 12, 4, 14, 7, 9, 5, 18, 5, 8, 12, 13, 5, 14, 5, 16, 9, 8, 7, 18, 5, 9, 8, 18, 5, 15, 4, 15, 12, 9, 4, 22, 8, 11, 10, 13, 5, 18, 6, 19, 10, 9, 6, 24, 6, 11, 11, 20, 9, 17, 6, 14, 10, 18, 4, 26, 7, 10, 11, 13, 9, 17, 4, 24, 17, 12, 9, 22 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..84.

S. S. Wagstaff, Jr., Main Tables from the Cunningham Project.

S. S. Wagstaff, Jr., The Cunningham Project

FORMULA

Mobius transform of A085032 - T. D. Noe, Jun 19 2003

CROSSREFS

Cf. A057951-A057958, A046051.

Cf. A085032.

Sequence in context: A119733 A140869 A111570 * A155896 A060710 A271853

Adjacent sequences:  A057951 A057952 A057953 * A057955 A057956 A057957

KEYWORD

nonn

AUTHOR

Patrick De Geest, Nov 15 2000.

STATUS

approved

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Last modified May 26 02:35 EDT 2019. Contains 323579 sequences. (Running on oeis4.)