%I
%S 0,1,2,3,23,27,33,63,158,278,290,351,471,797,8462,28793,266030
%N Numbers n such that 6*5^n + 1 is prime.
%C Primes found and proved by PrimeForm.
%C All terms correspond to verified primes, that is, not merely probable primes.  _Robert Price_, Jan 16 2015
%C a(18) > 3*10^5.  _Robert Price_, Jan 16 2015
%t Select[Range[0, 10000], PrimeQ[6*5^# + 1] &] (* _Robert Price_, Jan 16 2015 *)
%o (PARI) is(n)=ispseudoprime(6*5^n+1) \\ _Charles R Greathouse IV_, Jun 06 2017
%K hard,nonn
%O 1,3
%A _Rick L. Shepherd_, Aug 04 2008
%E a(17) from _Robert Price_, Jan 16 2015
