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A128352 Numbers k such that (17^k - 5^k)/12 is prime. 19
5, 7, 17, 23, 43, 71, 239, 733, 1097 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
All terms are primes.
a(10) > 10^5. - Robert Price, Jun 11 2013
LINKS
MATHEMATICA
k=17; Do[p=Prime[n]; f=(k^p-5^p)/(k-5); If[ PrimeQ[f], Print[p] ], {n, 1, 100}]
PROG
(PARI) is(n)=isprime((17^n-5^n)/12) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
Sequence in context: A166109 A157755 A265812 * A025085 A175238 A240030
KEYWORD
nonn,hard,more
AUTHOR
Alexander Adamchuk, Feb 27 2007
STATUS
approved

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Last modified April 18 22:18 EDT 2024. Contains 371782 sequences. (Running on oeis4.)