A220701 Numbers k such that k^3 + 3*k + 3^k is prime.

1, 2, 4, 5, 7, 17, 22, 47, 155, 167, 203, 277, 469, 629, 890, 1427, 4507, 5705, 6095, 9808, 10108, 12797, 16184, 31535, 33575

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Mathematica

Select[Range[10000], PrimeQ[#^3 + 3*# + 3^#]&]

Prog

(PARI) is(n)=ispseudoprime(n^3+3*n+3^n) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A220509.

Sequence in context: A019277 A127791 A290431 * A005620 A049915 A244332

Adjacent sequences: A220698 A220699 A220700 * A220702 A220703 A220704

Keyword

nonn,more

Author

Vincenzo Librandi, Jan 07 2013

Extensions

a(21)-a(25) from Michael S. Branicky, Jul 13 2023

Status

approved