A113826 - OEIS

%I #12 Sep 08 2022 08:45:23

%S 1,3,6,7,8,9,11,16,25,32,35,38,40,48,50,54,58,65,77,78,79,87,95,97,

%T 103,112,117,119,122,134,135,141,145,155,156,159,161,172,175,193,209,

%U 218,219,220,221,223,231,233,246,280,290,296,297,304,309,310,311,322,327

%N Numbers n such that (n+1)^7 - n^7 is prime.

%H Vincenzo Librandi, <a href="/A113826/b113826.txt">Table of n, a(n) for n = 1..1000</a>

%p L:= NULL: for x from 1 to 1000 do if isprime((x+1)^7 - x^7) then L:= L, x fi od: L;

%t Flatten[Position[Partition[Range[400]^7,2,1],_?(PrimeQ[Last[#]- First[ #]]&), {1},Heads->False]] (* _Harvey P. Dale_, Aug 20 2013 *)

%t Select[Range[0, 400], PrimeQ[(# + 1)^7 - #^7] &] (* _Vincenzo Librandi_, Apr 20 2014 *)

%o (Magma) [n: n in [0..350] | IsPrime((n+1)^7-n^7)]; // _Vincenzo Librandi_, Apr 20 2014

%o (PARI) is(n)=isprime((n+1)^7-n^7) \\ _Charles R Greathouse IV_, Jun 06 2017

%K easy,nonn

%O 1,2

%A _Robert Israel_, Jan 24 2006