

A128343


Numbers n such that (14^n + 5^n)/19 is prime.


11




OFFSET

1,1


COMMENTS

All terms are primes.
a(8) > 10^5.  Robert Price, May 20 2013


LINKS

Table of n, a(n) for n=1..7.


MATHEMATICA

k=14; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n, 1, 100}]


PROG

(PARI) is(n)=isprime((14^n+5^n)/19) \\ Charles R Greathouse IV, Feb 17 2017


CROSSREFS

Cf. A057171, A082387, A122853, A128335, A128336, A128337, A128338, A128339, A128340, A128341, A128342. Cf. A004061, A082182, A121877, A059802. Cf. A062572, A128344, A128345, A128346, A128347, A128348, A128349, A128350, A128351, A128352, A128353, A128354.
Sequence in context: A264765 A247196 A246764 * A106877 A041949 A222452
Adjacent sequences: A128340 A128341 A128342 * A128344 A128345 A128346


KEYWORD

hard,more,nonn


AUTHOR

Alexander Adamchuk, Feb 27 2007


EXTENSIONS

a(5)a(7) from Robert Price, May 20 2013


STATUS

approved



