A217492 Numbers k such that 9^k + 10 is prime.

0, 1, 3, 4, 9, 18, 49, 57, 67, 69, 106, 126, 258, 583, 1221, 1366, 4311, 11361, 12621, 14964, 16017, 22467, 25434, 45094, 51051, 89113

Offset: 1

Author

Vincenzo Librandi, Oct 05 2012

Keywords

• nonn
• more
• hard

Comments

Contains exactly the halved even terms of A217137.

Crossrefs

Cf. A217137, A217347.

Programs

Mathematica

Select[Range[5000], PrimeQ[9^# + 10] &] (* Vincenzo Librandi, Oct 05 2012 *)

PARI

is(n)=ispseudoprime(9^n+10) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(18)-a(26) added from the data at A217137 by Amiram Eldar, Jun 19 2022