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A185230
Numbers n such that (33^n + 1)/34 is prime.
1
5, 67, 157, 12211, 313553
OFFSET
1,1
COMMENTS
All terms are prime.
a(5) > 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[ (33^p + 1)/34 ], Print[p] ], {n, 1, 9592} ]
PROG
(PARI) is(n)=ispseudoprime((33^n+1)/34) \\ Charles R Greathouse IV, Jun 13 2017
KEYWORD
bref,hard,more,nonn
AUTHOR
Robert Price, Aug 29 2013
EXTENSIONS
a(5) from Paul Bourdelais, Feb 26 2021
STATUS
approved