A177106 Numbers n for which n^5-n-1 is not prime.

6, 7, 8, 9, 12, 13, 14, 18, 22, 23, 24, 25, 26, 29, 31, 32, 33, 35, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 49, 51, 52, 53, 54, 55, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 76, 77, 78, 79, 80, 81, 83, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 98

Offset: 1

Author

Vincenzo Librandi, Jun 25 2010

Keywords

• nonn

Comments

Includes all numbers == 6 or 8 (mod 17). - Robert Israel, Jul 14 2019

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A126427 (Numbers n for which n^5-n-1 is prime).

Programs

Maple

remove(t -> isprime(t^5-t-1), [$2..200]); # Robert Israel, Jul 14 2019

Mathematica

Select[Range[100],CompositeQ[#^5-#-1]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 18 2019 *)