A216424 Numbers k such that 4^k + k^4 - 1 is prime.

2, 16, 74, 164, 518, 796, 8756, 12598

Offset

1,1

Comments

a(9) > 10^5. - Robert Price, Feb 04 2014

Links

Table of n, a(n) for n=1..8.

Mathematica

Select[Range[0, 5000], PrimeQ[4^# + #^4 - 1] &]

Prog

(Magma) [n: n in [0..800] | IsPrime(4^n+n^4-1)];
(PARI) is(n)=ispseudoprime(4^n+n^4-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A100357, A215434-A215437, A215439-A215446, A216375.

Sequence in context: A208063 A207923 A207839 * A212897 A289837 A323297

Adjacent sequences: A216421 A216422 A216423 * A216425 A216426 A216427

Keyword

nonn

Author

Vincenzo Librandi, Sep 07 2012

Extensions

a(7)-a(8) from Robert Price, Feb 04 2014

Status

approved