A220787 Numbers k such that k^11 + 11*k + 11^k is prime.

1, 15, 18, 167, 684, 698, 1642, 3691, 4245, 5370, 6238, 6926, 9646, 10656, 10999, 11868, 14188, 35787

Offset: 1

Author

Vincenzo Librandi, Jan 07 2013

Keywords

• nonn
• more

Comments

a(13) > 9000. - Tyler NeSmith, Jul 26 2021

Crossrefs

Cf. A220653.

Programs

Mathematica

Select[Range[5000], PrimeQ[#^11 + 11*# + 11^#]&]

PARI

is(n)=ispseudoprime(n^11+11*n+11^n) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(10)-a(12) from Tyler NeSmith, Jul 26 2021

a(13)-a(15) from Michael S. Branicky, Jan 13 2023

a(16)-a(17) from Michael S. Branicky, Apr 22 2023

a(18) from Michael S. Branicky, Sep 19 2024