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A215441
Numbers k such that 3^k + k^3 + 1 is prime.
4
0, 1, 7, 39, 97, 115, 199, 1287, 1411, 2713, 4647, 84985
OFFSET
1,3
COMMENTS
a(13) > 2*10^5. - Robert Price, Mar 06 2014
MATHEMATICA
Select[Range[0, 5000], PrimeQ[3^# + #^3 + 1] & ]
PROG
(Magma) [n: n in [0..800] | IsPrime(3^n+n^3+1)];
(PARI) is(n)=isprime(3^n+n^3+1) \\ Charles R Greathouse IV, Mar 06 2014
CROSSREFS
Cf. A215436.
Sequence in context: A158576 A304012 A329528 * A373539 A027482 A352310
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Sep 03 2012
EXTENSIONS
a(12) from Robert Price, Mar 06 2014
STATUS
approved