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A057953 Number of prime factors of 8^n - 1 (counted with multiplicity). 2
1, 3, 2, 5, 3, 6, 4, 7, 3, 7, 4, 10, 4, 8, 6, 10, 5, 9, 4, 13, 7, 9, 4, 14, 7, 8, 6, 14, 6, 13, 3, 13, 8, 11, 11, 15, 6, 9, 9, 17, 5, 14, 5, 15, 10, 9, 6, 19, 7, 14, 8, 18, 8, 16, 10, 19, 7, 11, 6, 24, 5, 8, 10, 16, 8, 17, 6, 20, 9, 22, 7, 21, 7, 13, 14, 17, 10, 16, 8, 23, 10, 12, 5, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

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 A085033 - T. D. Noe, Jun 19 2003

MATHEMATICA

PrimeOmega/@(8^Range[90]-1) (* Harvey P. Dale, May 24 2018 *)

CROSSREFS

Cf. A057951-A057958, A046051.

Cf. A085033.

Sequence in context: A057958 A225411 A247815 * A129231 A166477 A124332

Adjacent sequences:  A057950 A057951 A057952 * A057954 A057955 A057956

KEYWORD

nonn

AUTHOR

Patrick De Geest, Nov 15 2000.

STATUS

approved

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Last modified February 19 18:22 EST 2019. Contains 320327 sequences. (Running on oeis4.)