A093713 - OEIS

%I #14 Mar 12 2023 08:49:04

%S 1,2,3,4,5,12,16,18,21,42,66,69,123,132,165,204,397,401,486,657,1005,

%T 1050,1882,2545,2813,3168,4092,4151,4469,5358,9168,11554,11866,80946

%N Numbers k such that 6^k - 5^(k-1) is prime.

%C a(35) > 10^5. - _Robert Price_, May 04 2016

%t Do[ If[ PrimeQ[6^n - 5^(n - 1)], Print[n]], {n, 2000}]

%o (PARI) is(n)=isprime(6^n-5^(n-1)) \\ _Charles R Greathouse IV_, Feb 17 2017

%Y Cf. A093765.

%K nonn,more

%O 1,2

%A Herman H. Rosenfeld (herm3(AT)pacbell.net) and _Robert G. Wilson v_, Jun 17 2004

%E a(24)-a(34) from _Robert Price_, May 04 2016