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Primes of the form k^4 - (k+1)^3.
4

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

%S 17,131,409,953,1889,8669,18539,60623,77689,122321,373049,437293,

%T 590267,2249441,8975009,9649303,11111117,14526289,19836689,26484839,

%U 31201649,56608289,67796273,80565889,84021983,87588089,107150489,150402113

%N Primes of the form k^4 - (k+1)^3.

%H Vincenzo Librandi, <a href="/A087191/b087191.txt">Table of n, a(n) for n = 1..5000</a>

%e a(2) = 4^4 - (4+1)^3 = 256 - 125 = 131.

%t Select[Table[n^4-(n+1)^3,{n,3,101900}],PrimeQ] (* _Vincenzo Librandi_, Dec 10 2011 *)

%o (Magma) [a: n in [3..120] | IsPrime(a) where a is n^4-(n+1)^3]; // _Vincenzo Librandi_, Dec 10 2011

%Y Cf. A087190 n such that n^4-(n+1)^3 is prime.

%K nonn,easy

%O 1,1

%A _Hugo Pfoertner_, Aug 24 2003