A272781 Numbers n such that 6^n-5^(n+1) is prime.

9, 14, 32, 48, 78, 85, 108, 134, 834, 1701, 2275, 3103, 5795, 10307, 17243, 24045, 31085, 32613, 40014

Offset: 1

Author

Robert Price, May 06 2016

Keywords

• nonn
• more

Comments

a(20) > 10^5.

Examples

			9 is a member since 6^9 - 5^10 = 10077696 - 9765625 = 312071 which is a prime number.
		

Crossrefs

Cf. A093713, A082103, A093717, A093793, A096185, A093794, A093795, A096186, A271883, A271884.

Programs

Mathematica

Select[Range[0, 100000], PrimeQ[6^# - 5^(# + 1)] &]

PARI

is(n)=ispseudoprime(6^n-5^(n+1)) \\ Charles R Greathouse IV, Jun 13 2017