|
%I #11 Sep 08 2022 08:45:51
%S 3,7,79,359,1031,1039,11311,47599
%N Primes p such that 2^p+23 is also prime.
%C a(9) > 5*10^5. - _Robert Price_, Sep 18 2015
%F A057203 INTERSECT A000040. [_R. J. Mathar_, Jul 06 2010]
%e For p=3, 2^3+23=31; p=7, 2^7+23=131; p=79, 2^79+23=604462909807314587353111
%t Select[Prime[Range[1000]], PrimeQ[2^#+23]&] (*_Robert Price_, Sep 18 2015 *)
%o (Magma) [p: p in PrimesUpTo(1000) | IsPrime(2^p+23) ]
%K nonn
%O 1,1
%A _Vincenzo Librandi_, Mar 09 2010
%E Two more terms from _R. J. Mathar_, Jul 06 2010
%E a(7)-a(8) from _Robert Price_, Sep 18 2015
| 