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A058888 Number of terms in the set invphi(2*p(n)), where p(n) is the n-th prime. 7
4, 4, 2, 0, 2, 0, 0, 0, 2, 2, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 2, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000

EXAMPLE

The set invphi(2*3)={7,9,14,18}. It has 4 terms, so a(2)=4, while invphi(2*1601)={3203,6406}, thus a(252)=2.

MAPLE

with(numtheory): [seq(nops(invphi(2*ithprime(i))), i=1..256)];

CROSSREFS

Cf. A000010, A005277, A007617, A002202, A071629-A071634.

Sequence in context: A120396 A141024 A173210 * A194678 A153015 A173635

Adjacent sequences:  A058885 A058886 A058887 * A058889 A058890 A058891

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 08 2001

EXTENSIONS

Offset corrected by Donovan Johnson, Apr 28 2013

STATUS

approved

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Last modified October 15 15:14 EDT 2019. Contains 328030 sequences. (Running on oeis4.)