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A236070 Primes p such that f(f(p)) is prime where f(x) = x^8 + 1. 0
7, 59, 163, 929, 977, 1373, 1549, 1619, 1913, 2113, 2593, 4397, 5417, 5651, 6397, 6659, 6833, 7351, 7793, 7883, 8641, 9719, 10091, 10477, 10949, 11243, 12239, 13441, 13457, 13691, 14753, 15349, 15467, 15971, 17747, 19051 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..36.

FORMULA

a(n) = (A235983(n)-1)^(1/8).

EXAMPLE

1619 is prime and (1619^8+1)^8+1 is also prime.

PROG

(Python)

import sympy

from sympy import isprime

{print(p) for p in range(10**5) if isprime(p) and isprime((p**8+1)**8+1)}

(PARI) isok(p) = isprime(p) && (q = p^8+1) && isprime(q^8+1); \\ Michel Marcus, Jan 19 2014

CROSSREFS

Cf. A235983.

Sequence in context: A140371 A181424 A142511 * A059705 A218201 A015568

Adjacent sequences:  A236067 A236068 A236069 * A236071 A236072 A236073

KEYWORD

nonn

AUTHOR

Michel Marcus and Derek Orr, Jan 19 2014

STATUS

approved

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Last modified January 21 23:44 EST 2022. Contains 350481 sequences. (Running on oeis4.)