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A235683
Numbers n such that (46^n + 1)/47 is prime.
3
7, 23, 59, 71, 107, 223, 331, 2207, 6841, 94841
OFFSET
1,1
COMMENTS
All terms up to a(10) are primes.
a(11) > 10^5.
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, Repunit.
MATHEMATICA
Do[ p=Prime[n]; If[ PrimeQ[ (46^p + 1)/47 ], Print[p] ], {n, 1, 9592} ]
PROG
(PARI) is(n)=ispseudoprime((46^n+1)/47) \\ Charles R Greathouse IV, May 22 2017
KEYWORD
hard,more,nonn
AUTHOR
Robert Price, Jan 13 2014
STATUS
approved