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A057957 Number of prime factors of 4^n - 1 (counted with multiplicity). 2
1, 2, 3, 3, 3, 5, 3, 4, 6, 6, 4, 7, 3, 6, 7, 5, 3, 10, 3, 8, 8, 7, 4, 10, 7, 7, 9, 8, 6, 13, 3, 7, 9, 7, 9, 14, 5, 7, 8, 10, 5, 14, 5, 10, 13, 9, 6, 13, 5, 14, 11, 10, 6, 15, 12, 11, 9, 9, 6, 17, 3, 8, 14, 9, 9, 15, 5, 11, 9, 16, 6, 19, 6, 10, 14, 11, 10, 18, 5, 13, 16, 10, 8, 19, 7, 10, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..87.

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

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

FORMULA

Mobius transform of A085029 - T. D. Noe, Jun 19 2003

CROSSREFS

Cf. A057951-A057958, A046051.

Cf. A085029.

Sequence in context: A103359 A020481 A066660 * A076559 A102601 A092308

Adjacent sequences:  A057954 A057955 A057956 * A057958 A057959 A057960

KEYWORD

nonn

AUTHOR

Patrick De Geest, Nov 15 2000.

STATUS

approved

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Last modified June 19 19:50 EDT 2013. Contains 226416 sequences.