A227046 Numbers k such that (17^k + 5^k)/22 is prime.

3, 29, 151, 2153, 5717, 9133, 9973, 79537

Offset: 1

Author

Robert Price, Jun 29 2013

Keywords

• hard
• more
• nonn

Comments

All terms are primes.

a(9) > 10^5.

Crossrefs

Cf. A128340, A128341, A128342, A128343, A057183.

Programs

Mathematica

k=17; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n, 1, 9592}]

PARI

is(n)=ispseudoprime((17^n+5^n)/22) \\ Charles R Greathouse IV, Feb 17 2017