A216421 Numbers k such that 13^k + k^13 + 1 is prime.

0, 9, 4371, 7985, 14711

Offset: 1

Author

Vincenzo Librandi, Sep 07 2012

Keywords

• nonn
• hard
• more

Comments

a(6) > 10^5. - Robert Price, Feb 23 2014

Crossrefs

Cf. A100357, A215434-A215446, A216375.

Programs

Mathematica

Select[Range[0, 5000], PrimeQ[13^# + #^13 + 1] &]

PARI

is(n)=ispseudoprime(13^n+n^13+1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(4)-a(5) from Robert Price, Feb 23 2014