A076513 - OEIS

%I #25 Apr 23 2022 22:17:31

%S 1,3,5,65,119,213,1209,2469,2669,3939,11219

%N Numbers n such that 2+2^n+3^n is prime.

%C 119, 213, 1209 and 2469 proved prime by Primo v1.2.1. - _Robert G. Wilson v_ Oct 17 2002

%C a(12) > 10^5. - _Giovanni Resta_, Mar 19 2014

%t Do[ If[ PrimeQ[2 + 2^n + 3^n], Print[n]], {n, 1, 4000, 2}]

%t Select[Range[10000], PrimeQ[2 + 2^# + 3^#] &] (* _Vincenzo Librandi: Oct 05 2012 *)

%o (PARI) is(n)=ispseudoprime(2+2^n+3^n) \\ _Charles R Greathouse IV_, Jun 13 2017

%Y Cf. A075996.

%K nonn,more

%O 1,2

%A _Zak Seidov_, Oct 17 2002

%E Edited and extended by _Robert G. Wilson v_, Oct 17 2002

%E a(10) from _Vincenzo Librandi_, Oct 05 2012

%E a(11) from _Giovanni Resta_, Feb 19 2013