

A057188


Numbers n such that (22^n+1)/23 is a prime.


14



3, 5, 13, 43, 79, 101, 107, 227, 353, 7393, 50287
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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

Table of n, a(n) for n=1..11.
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
Adjacent sequences: A057185 A057186 A057187 * A057189 A057190 A057191


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane, Sep 15 2000


EXTENSIONS

a(11) from Robert Price, Jun 02 2013


STATUS

approved



