# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a247960 Showing 1-1 of 1 %I A247960 #28 Sep 08 2022 08:46:10 %S A247960 0,1,9,23,681,2487 %N A247960 Numbers n such that 41^n + 2 is prime. %C A247960 All terms > 0 are odd. - _Robert Israel_, Sep 29 2014 %C A247960 a(7) > 2*10^5. - _Robert Price_, May 08 2015 %t A247960 Select[Range[0, 2000], PrimeQ[41^# + 2] &] %o A247960 (Magma) [n: n in [0..600]| IsPrime( 41^n + 2 )]; %o A247960 (PARI) is(n)=ispseudoprime(41^n+2) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A247960 Cf. similar sequences listed in A247957. %K A247960 nonn,more %O A247960 1,3 %A A247960 _Vincenzo Librandi_, Sep 29 2014 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE