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A344361 Primes p such that (2^p-2)/p - 1 is prime. 1
5, 7, 349, 1123, 25447 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(6) > 1199999, if it exists. - Karl-Heinz Hofmann, Jul 27 2021

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

7 is a term because (2^7-2)/7 - 1 = 17 is prime.

PROG

(PARI) is(p) = isprime(p) && ispseudoprime((2^p-2)/p-1) \\ Jinyuan Wang, May 15 2021

CROSSREFS

Cf. A064535, A344360.

Sequence in context: A196309 A196281 A196331 * A159019 A059394 A176960

Adjacent sequences:  A344358 A344359 A344360 * A344362 A344363 A344364

KEYWORD

nonn,more

AUTHOR

Jorge Coveiro, May 15 2021

EXTENSIONS

a(5) from Hugo Pfoertner, May 17 2021

STATUS

approved

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Last modified September 25 22:56 EDT 2022. Contains 356986 sequences. (Running on oeis4.)