The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A128343 Numbers n such that (14^n + 5^n)/19 is prime. 11
 3, 7, 17, 79, 17477, 19319, 49549 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are primes. a(8) > 10^5. - Robert Price, May 20 2013 LINKS 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 22 04:27 EST 2020. Contains 331133 sequences. (Running on oeis4.)