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A057188
Numbers n such that (22^n+1)/23 is a prime.
14
3, 5, 13, 43, 79, 101, 107, 227, 353, 7393, 50287
OFFSET
1,1
COMMENTS
Some of the larger terms may only correspond to probable primes.
a(12) > 10^5 - Robert Price, Jun 02 2013
LINKS
H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.
PROG
(PARI) isok(n) = (denominator(p=(22^n+1)/23)==1) && isprime(p); \\ Michel Marcus, Oct 30 2017
CROSSREFS
Sequence in context: A259932 A178432 A236068 * A128548 A321358 A113606
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Sep 15 2000
EXTENSIONS
a(11) from Robert Price, Jun 02 2013
STATUS
approved