A215440 Numbers k such that 3^k + k^3 - 1 is prime.

1, 3, 5, 9, 65, 71, 225, 269, 651, 843, 1971, 4851, 13667, 13961, 33309, 168111

Offset

1,2

Comments

a(17) > 2*10^5. - Robert Price, Apr 15 2014

Links

Table of n, a(n) for n=1..16.

Mathematica

Select[Range[0, 3000], PrimeQ[3^# + #^3 - 1] &]

Prog

(Magma) [n: n in [0..800] | IsPrime(3^n + n^3 - 1)]
(PARI) is(n)=ispseudoprime(3^n+n^3-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A215435.

Sequence in context: A055289 A124974 A336144 * A163550 A123220 A098339

Adjacent sequences: A215437 A215438 A215439 * A215441 A215442 A215443

Keyword

nonn

Author

Vincenzo Librandi, Sep 03 2012

Extensions

a(12)-a(16) from Robert Price, Apr 15 2014

Status

approved