# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a128029 Showing 1-1 of 1 %I A128029 #11 Feb 17 2017 11:56:07 %S A128029 2,5,13,67,2657,3547,15649 %N A128029 Numbers n such that (14^n - 3^n)/11 is prime. %C A128029 All terms are primes. %C A128029 There is no further term up to prime(1400)=11657. - _Farideh Firoozbakht_, Apr 04 2007 %C A128029 No other terms < 100,000. %t A128029 k=11; Select[ Prime[ Range[1,200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ] %o A128029 (PARI) is(n)=isprime((14^n-3^n)/11) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A128029 Cf. A028491 = numbers n such that (3^n - 1)/2 is prime. Cf. A057468 = numbers n such that 3^n - 2^n is prime. Cf. A059801 = numbers n such that 4^n - 3^n is prime. Cf. A121877 = numbers n such that (5^n - 3^n)/2 is a prime. Cf. A128024, A128025, A128026, A128027, A128028, A128030, A128031, A128032. %K A128029 hard,nonn %O A128029 1,1 %A A128029 _Alexander Adamchuk_, Feb 11 2007 %E A128029 More terms from _Farideh Firoozbakht_, Apr 04 2007 %E A128029 Added term a(7)=15649 by _Robert Price_, Sep 12 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE