A217136 Numbers k such that 3^k + 8 is prime.

1, 2, 4, 5, 8, 13, 14, 20, 38, 44, 77, 88, 124, 152, 244, 557, 2429, 4382, 6268, 18488, 75097, 81998, 96460, 143497

Offset: 1

Author

Vincenzo Librandi, Oct 01 2012

Keywords

• nonn

Comments

a(25) > 2*10^5. - Robert Price, Sep 25 2013

Crossrefs

Cf. A014224, A051783, A058958, A058959.

Programs

Mathematica

Select[Range[0, 5000], PrimeQ[3^# + 8] &]

PARI

for(n=1, 5*10^3, if(isprime(3^n+8), print1(n", ")))

Extensions

a(19)-a(24) from Robert Price, Sep 25 2013