A113868 - OEIS

%I #16 Feb 10 2020 14:07:43

%S 1,19,21,45,73,75,103,109,111,139,195,205,211,321,331,385,433,439,571,

%T 601,763,765,805,811,819,985,1069,1075,1159,1333,1395,1401,1431,1459,

%U 1573,1629,1635,1659,1759,1801,2025,2035,2065,2079,2131,2133,2191,2199

%N Numbers k such that (k+1)^9 - 3 is prime.

%H Daniel Starodubtsev, <a href="/A113868/b113868.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A112405(n) - 1. - _Daniel Starodubtsev_, Feb 10 2020

%e If k=139 then (139+1)^9 - 3 = 20661046783999999997 (prime).

%t Do[If[PrimeQ[(n + 1)^9 - 3], Print[n]], {n, 1, 2200}] (Steinerberger)

%o MAGMA) [n: n in [1..100000] | IsPrime((n+1)^9-3)]; // _Vincenzo Librandi_, Nov 13 2010

%o (PARI) is(n)=isprime((n+1)^9-3) \\ _Charles R Greathouse IV_, Jun 13 2017

%Y Cf. A112405.

%K nonn,easy

%O 1,2

%A _Parthasarathy Nambi_, Jan 25 2006

%E More terms from _Stefan Steinerberger_, Jan 27 2006