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A057182 Numbers n such that (16^n + 1)/17 is a prime. 19
3, 5, 7, 23, 37, 89, 149, 173, 251, 307, 317, 30197, 1025393 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..13.

Paul Bourdelais, A Generalized Repunit Conjecture

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.

H. Lifchitz, Mersenne and Fermat primes field

Eric Weisstein's World of Mathematics, Ferrier's Prime

MATHEMATICA

m = 16; Select[Range[0, 10^3], PrimeQ[(m^# + 1)/(m + 1)] & ] (* Robert Price, Oct 15 2018 *)

PROG

(PRIME95) PRP=1, 2, 4101572, 1, 0, 0, "17"

CROSSREFS

Subsequence of A195439. [Arkadiusz Wesolowski, Dec 18 2011]

Sequence in context: A154764 A320256 A101773 * A038916 A019363 A288890

Adjacent sequences:  A057179 A057180 A057181 * A057183 A057184 A057185

KEYWORD

hard,more,nonn

AUTHOR

N. J. A. Sloane, Sep 15 2000

EXTENSIONS

a(12) from Robert G. Wilson v, Apr 11 2005

a(13) gives a probable prime discovered by Paul Bourdelais, Aug 20 2014

STATUS

approved

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Last modified December 14 09:41 EST 2019. Contains 329979 sequences. (Running on oeis4.)