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A245237 Numbers n such that (48^n - 1)/47 is prime. 3
19, 269, 349, 383, 1303, 15031, 200443 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(7) > 10^5.

All terms are prime.

LINKS

Table of n, a(n) for n=1..7.

Harvey Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.

Henri Lifchitz, Mersenne and Fermat primes field

MAPLE

A245237:=n->`if`(isprime((48^n - 1)/47), n, NULL); seq(A245237(n), n=1..100000); # Wesley Ivan Hurt, Apr 12 2014

MATHEMATICA

Select[Prime[Range[100000]], PrimeQ[(48^# - 1)/47] &]

PROG

(PARI) is(n)=ispseudoprime((48^n-1)/47) \\ Charles R Greathouse IV, Jun 06 2017

CROSSREFS

Cf. A028491, A004061, A004062, A004063, A004023, A005808, A004064, A016054, A006032, A006033, A006034, A006035, A127995, A127996, A127997, A127998, A127999, A098438, A128002, A128003, A128004, A128005, A240765, A242797, A243279.

Sequence in context: A016254 A016302 A253217 * A141942 A181043 A142899

Adjacent sequences:  A245234 A245235 A245236 * A245238 A245239 A245240

KEYWORD

hard,more,nonn

AUTHOR

Robert Price, Jul 14 2014

EXTENSIONS

a(7) corresponds to a probable prime discovered by Paul Bourdelais, Aug 04 2020

STATUS

approved

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Last modified March 3 01:22 EST 2021. Contains 341756 sequences. (Running on oeis4.)