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

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

Offset

1,1

Comments

All terms are primes.

a(9) > 10^5.

Links

Table of n, a(n) for n=1..8.

Mathematica

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

Prog

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

Crossrefs

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

Sequence in context: A024386 A171355 A163854 * A094809 A096028 A137786

Adjacent sequences: A227043 A227044 A227045 * A227047 A227048 A227049

Keyword

hard,more,nonn

Author

Robert Price, Jun 29 2013

Status

approved