A215443 Numbers k such that 5^k + k^5 - 1 is prime.

1, 3, 9, 13, 27, 225, 505, 1605, 7417, 9193, 9235

Offset: 1

Author

Vincenzo Librandi, Sep 03 2012

Keywords

• nonn
• more

Comments

a(12) > 2*10^5. - Robert Price, May 24 2014

Crossrefs

Cf. A215437.

Programs

Magma

[k: k in [0..300] | IsPrime(5^k + k^5 - 1)];

Mathematica

Select[Range[0, 3000], PrimeQ[5^# + #^5 - 1] &]

PARI

is(n)=ispseudoprime(5^n+n^5-1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(9)-a(11) from Robert Price, May 24 2014