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Numbers n such that n^4-(n+1)^3 is prime.
2

%I #9 Sep 08 2022 08:45:11

%S 3,4,5,6,7,10,12,16,17,19,25,26,28,39,55,56,58,62,67,72,75,87,91,95,

%T 96,97,102,111,114,115,116,124,126,128,132,137,152,160,161,172,181,

%U 182,184,191,198,201,205,208,209,213,214,217,220,223,227,235,237,247,248,250

%N Numbers n such that n^4-(n+1)^3 is prime.

%H Vincenzo Librandi, <a href="/A087190/b087190.txt">Table of n, a(n) for n = 1..5000</a>

%e a(1)=3 because 3^4-(3+1)^3=81-64=17 is prime.

%t lst={};Do[If[PrimeQ[n^4-(n+1)^3],AppendTo[lst,n]],{n,3,1000}];lst (* _Vincenzo Librandi_, Jul 16 2012 *)

%o (Magma) [n: n in [3..300]| IsPrime(n^4-(n+1)^3)]; // _Vincenzo Librandi_, Jul 16 2012

%o (PARI) is(n)=isprime(n^4-(n+1)^3) \\ _Charles R Greathouse IV_, Jun 05 2017

%Y Cf. A087191 primes of the form n^4-(n+1)^3.

%K nonn,easy

%O 1,1

%A _Hugo Pfoertner_, Aug 23 2003