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URL: https://oeis.org/A128070

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A128070
Numbers k such that (3^k + 11^k)/14 is prime.
9
3, 103, 271, 523, 23087, 69833
OFFSET
1,1
COMMENTS
All terms are primes.
a(7) > 10^5. - Robert Price, Mar 04 2013
MATHEMATICA
k=11; Do[ p=Prime[n]; f=(3^p+k^p)/(k+3); If[ PrimeQ[f], Print[p]], {n, 1, 100} ]
PROG
(PARI) is(n)=isprime((3^n+11^n)/14) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
Cf. A007658 (numbers k such that (3^k + 1)/4 is prime).
Cf. A057469 (numbers k such that (3^k + 2^k)/5 is prime).
Cf. A122853 (numbers k such that (3^k + 5^k)/8 is prime).
Cf. A059801 (numbers k such that 4^k - 3^k is prime).
Cf. A121877 (numbers k such that (5^k - 3^k)/2 is prime).
Sequence in context: A364418 A157600 A139908 * A323036 A101780 A197632
KEYWORD
hard,more,nonn
AUTHOR
Alexander Adamchuk, Feb 14 2007
EXTENSIONS
a(5)-a(6) from Robert Price, Mar 04 2013
STATUS
approved