A057182 - OEIS

A057182

Numbers n such that (16^n + 1)/17 is a prime.

3, 5, 7, 23, 37, 89, 149, 173, 251, 307, 317, 30197, 1025393

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OFFSET

1,1

LINKS

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.

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]

KEYWORD

hard,more,nonn

AUTHOR

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