login
A272781
Numbers n such that 6^n-5^(n+1) is prime.
0
9, 14, 32, 48, 78, 85, 108, 134, 834, 1701, 2275, 3103, 5795, 10307, 17243, 24045, 31085, 32613, 40014
OFFSET
1,1
COMMENTS
a(20) > 10^5.
EXAMPLE
9 is a member since 6^9 - 5^10 = 10077696 - 9765625 = 312071 which is a prime number.
MATHEMATICA
Select[Range[0, 100000], PrimeQ[6^# - 5^(# + 1)] &]
PROG
(PARI) is(n)=ispseudoprime(6^n-5^(n+1)) \\ Charles R Greathouse IV, Jun 13 2017
KEYWORD
nonn,more
AUTHOR
Robert Price, May 06 2016
STATUS
approved