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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A128350 Numbers k such that (14^k - 5^k)/9 is prime. 18
 2, 151, 673, 709, 2999, 17909, 77213 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are primes. a(8) > 10^5. - Robert Price, Apr 23 2013 LINKS MATHEMATICA k=14; Do[p=Prime[n]; f=(k^p-5^p)/(k-5); If[ PrimeQ[f], Print[p] ], {n, 1, 200}] PROG (PARI) is(n)=isprime((14^n-5^n)/9) \\ Charles R Greathouse IV, Feb 17 2017 CROSSREFS Cf. A062572, A128344, A128345, A128346, A128347, A128348, A128349, A128351, A128352, A128353, A128354. Cf. A004061, A082182, A121877, A059802. Cf. A057171, A082387, A122853, A128335, A128336, A128337, A128338, A128339, A128340, A128341, A128342. Sequence in context: A141139 A141130 A157074 * A046473 A261967 A024245 Adjacent sequences:  A128347 A128348 A128349 * A128351 A128352 A128353 KEYWORD hard,more,nonn AUTHOR Alexander Adamchuk, Feb 27 2007 EXTENSIONS One more term from Herman Jamke (hermanjamke(AT)fastmail.fm), May 01 2008 a(6) and a(7) from Robert Price, Apr 23 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 February 23 23:59 EST 2020. Contains 332195 sequences. (Running on oeis4.)