

A117705


Numbers n such that 5^nn^5 is prime.


10




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..5.
Henri & Renaud Lifchitz, PRP Records.


EXAMPLE

a(1)=2 because 2^5  5^2 = 7 is prime


MATHEMATICA

Do[If[PrimeQ[(5^nn^5)], Print[n]], {n, 1, 5000}]


PROG

(PARI) is(n)=isprime(5^nn^5) \\ Charles R Greathouse IV, Feb 17 2017


CROSSREFS

Sequence in context: A032461 A072390 A213136 * A330789 A031079 A200039
Adjacent sequences: A117702 A117703 A117704 * A117706 A117707 A117708


KEYWORD

hard,more,nonn


AUTHOR

Mohammed Bouayoun (Mohammed.Bouayoun(AT)sanef.com), Apr 13 2006, Jan 08 2008


EXTENSIONS

a(5) found by Donovan Johnson
First five terms confirmed by Dmitry Kamenetsky, Dec 18 2008


STATUS

approved



