A224984 - OEIS

%I #11 Jul 29 2013 12:01:48

%S 7,13,311,1637,4363,10433,41669,45631

%N Numbers n such that (14^n + 13^n)/27 is prime.

%C All terms are prime.

%C a(9) > 10^5.

%t Select[ Prime[ Range[1, 100000] ], PrimeQ[ (14^# + 13^#)/27 ]& ]

%o (PARI) forprime(p=3,10^6, if(ispseudoprime((14^p + 13^p)/27), print1(p,", ") ) ); \\ _Joerg Arndt_, Jul 29 2013

%Y Cf. A057180, A128072, A128343, A181141, A187819, A217095, A185239, A213216.

%K hard,nonn,more

%O 1,1

%A _Robert Price_, Apr 22 2013

%E Removed incorrect first term of "2".