A219616 Numbers k such that 5^k + k^4 is prime.

2, 4, 6, 8, 24, 28, 36, 54, 92, 154, 234, 442, 1138, 2408, 58564

Offset: 1

Author

Vincenzo Librandi, Nov 26 2012

Keywords

• nonn
• more

Crossrefs

Cf. A182359, A059802.

Programs

Magma

/* The code gives only the terms up to 442: */ [n: n in [0..1000 by 2] | IsPrime(5^n + n^4)];

Mathematica

Select[Range[0, 10000, 2], PrimeQ[(5^# + #^4)] &]

PARI

is(n)=ispseudoprime(5^n+n^4) \\ Charles R Greathouse IV, Jul 01 2013

Extensions

a(15) from Michael S. Branicky, Oct 09 2024