A225191 Numbers n such that (15^n + 2^n)/17 is prime.

3, 67, 199, 479, 563, 2243, 2579, 6599, 7951, 10099, 10909, 13759

Offset: 1

Author

Robert Price, May 07 2013

Keywords

• nonn
• hard
• more

Comments

All terms are odd primes.

a(13) > 10^5.

Crossrefs

Cf. A057181, A125956, A125957, A222265.

Programs

Mathematica

Select[Prime[Range[1, 100000]], PrimeQ[(15^# + 2^#)/17]&]

PARI

forprime(p=3,10^6, if(ispseudoprime((15^p + 2^p)/17), print1(p,", ") ) ); \\ Joerg Arndt, Jul 29 2013

Extensions

Removed incorrect first term of "2".