%I
%S 2,3,5,7,17,19,23,41,67,71,83,89,97,103,113,131,137,151,257,263,311,
%T 313,337,359,401,409,547,563,569,577,593,599,617,631,641,643,659,787,
%U 823,839,857,883,919
%N Decimal primes whose decimal representation in base 16 is also prime.
%H Vincenzo Librandi, <a href="/A089968/b089968.txt">Table of n, a(n) for n = 1..1000</a>
%e 43 is prime in decimal and 43 base 16 is 67 which is also prime in decimal.
%t b16Q[n_]:= Module[{idn16=IntegerDigits[n, 16]}, Max[idn16]<10&&PrimeQ[FromDigits[idn16]]]; Select[Prime[Range[PrimePi[2000]]], b16Q] (* _Vincenzo Librandi_, Apr 18 2013 *)
%K base,nonn
%O 1,1
%A _Cino Hilliard_, Jan 18 2004
