A057189 Numbers n such that (23^n+1)/24 is a prime.

11, 13, 67, 109, 331, 587, 24071, 29881, 44053

Offset: 1

Author

N. J. A. Sloane, Sep 15 2000

Keywords

• nonn
• more

Comments

Some of the larger terms may only correspond to probable primes.

a(10) > 10^5. - Robert Price, Jun 04 2013

Links

• H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.

Programs

PARI

isok(n) = (denominator(p=(23^n+1)/24)==1) && isprime(p); \\ Michel Marcus, Oct 30 2017

Extensions

a(7)-a(9) from Robert Price, Jun 04 2013