A236371 Numbers n such that 7^n - 12 is prime.

2, 3, 4, 12, 27, 28, 34, 36, 147, 179, 242, 276, 278, 466, 735, 2371, 4548, 5606, 10324, 82899

Offset: 1

Author

Robert Price, Jan 23 2014

Keywords

• nonn

Comments

a(21) > 10^5.

Crossrefs

Cf. A236371, A217131, A191469, A090669, A096305, A217130, A217132, A152213.

Programs

Mathematica

Select[Range[1, 100000], PrimeQ[7^# - 12] &]

PARI

for(n=1, 5*10^5, if(isprime(7^n-12), print1(n, ", ")))