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A123488 Smallest prime of the form (q^p-1)/(q-1), where p = prime(n) and q is prime too (q = A123487(n)). 3
3, 7, 31, 127, 12207031, 8191, 131071, 524287, 1484520425576434196455942238665054573307722183, 10333327940128053377465393536117755205850522803739374960650929 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Corresponding smallest primes q are listed in A123487.

a(n) coincides with A084732(n) when A066180(n) is prime or 0.

LINKS

Table of n, a(n) for n=1..10.

FORMULA

a(n) = (A123487(n)^prime(n) - 1) / (A123487(n) - 1).

CROSSREFS

Cf. A123487, A066180, A084732.

Sequence in context: A000668 A136007 A084732 * A121620 A042271 A000644

Adjacent sequences:  A123485 A123486 A123487 * A123489 A123490 A123491

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Sep 30 2006

STATUS

approved

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Last modified July 27 04:25 EDT 2017. Contains 289841 sequences.