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A268479 For p = prime(n), number of primes (including p) in the trajectory of p under the procedure in A244550, also allowing the Wieferich prime 2, that are not terms of a repeating cycle. 3
0, 0, 1, 2, 0, 1, 1, 1, 2, 1, 3, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
a(15) is unknown, since there is no known Wieferich prime to base 47 (cf. Fischer link).
LINKS
EXAMPLE
The trajectory of 31 starts 31, 7, 5, 2, 1093, 2, 1093, 2, 1093, ...., entering a repeating cycle consisting of the terms 2 and 1093. There are three terms before the cycle, so a(11) = 3.
CROSSREFS
Sequence in context: A287356 A029402 A330443 * A035196 A287475 A158020
KEYWORD
nonn,hard,more
AUTHOR
Felix Fröhlich, Feb 05 2016
STATUS
approved

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Last modified March 3 15:08 EST 2024. Contains 370512 sequences. (Running on oeis4.)