A089919 - OEIS

%I #13 Jul 07 2024 03:00:29

%S 1,3,12,13,66,100,369

%N Numbers k such that 3^prime(k) - 2 is prime.

%C No additional terms up to n=1000. - _Harvey P. Dale_, Oct 10 2016

%C a(8) > 91500, if it exists (based on the data at A014224). - _Amiram Eldar_, Jul 07 2024

%F a(n) = A000720(A086218(n)). - _Amiram Eldar_, Jul 07 2024

%t Select[Range[370],PrimeQ[3^Prime[#]-2]&] (* _Harvey P. Dale_, Oct 10 2016 *)

%o (PARI) f(n) = for(x=1,n,if(ispseudoprime(3^prime(x)-2),print1(x,",")))

%Y Cf. A000720, A014224, A086218.

%K nonn,more

%O 1,2

%A _Cino Hilliard_, Jan 11 2004

%E Definition corrected by _Jorge Coveiro_, Jan 31 2006, Jul 25 2006