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A057956 Number of prime factors of 5^n - 1 (counted with multiplicity). 17
2, 4, 3, 6, 4, 7, 3, 8, 5, 7, 3, 10, 3, 7, 7, 11, 4, 11, 5, 11, 6, 8, 4, 13, 8, 7, 9, 10, 5, 14, 4, 14, 6, 8, 9, 16, 5, 10, 6, 15, 4, 16, 4, 12, 12, 8, 3, 17, 4, 13, 8, 12, 5, 19, 10, 13, 7, 9, 4, 21, 5, 9, 11, 18, 8, 15, 7, 14, 9, 16, 4, 22, 5, 10, 16, 14, 7, 14, 5, 20, 11, 10, 5, 22, 9, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..502 (first 448 terms from Amiram Eldar)
S. S. Wagstaff, Jr., The Cunningham Project
FORMULA
Mobius transform of A085030. - T. D. Noe, Jun 19 2003
a(n) = A001222(A024049(n)). - Amiram Eldar, Feb 01 2020
MATHEMATICA
PrimeOmega[5^Range[90]-1] (* Harvey P. Dale, Dec 16 2017 *)
CROSSREFS
bigomega(b^n-1): A057951 (b=10), A057952 (b=9), A057953 (b=8), A057954 (b=7), A057955 (b=6), this sequence (b=5), A057957 (b=4), A057958 (b=3), A046051 (b=2).
Sequence in context: A341844 A372713 A015049 * A151734 A175027 A269837
KEYWORD
nonn
AUTHOR
Patrick De Geest, Nov 15 2000
STATUS
approved

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Last modified July 14 05:06 EDT 2024. Contains 374291 sequences. (Running on oeis4.)