login
A126421
Numbers n for which n^3-n-1 is prime.
20
2, 3, 4, 8, 9, 11, 14, 15, 16, 18, 21, 23, 24, 29, 31, 35, 36, 38, 41, 45, 48, 55, 58, 59, 60, 64, 69, 70, 71, 76, 81, 86, 98, 104, 108, 111, 113, 115, 119, 123, 126, 128, 130, 136, 140, 150, 151, 155, 163, 168, 174, 176, 183, 184, 185, 186, 188, 189, 191, 203, 206
OFFSET
1,1
MATHEMATICA
a = {}; Do[If[PrimeQ[x^3 - x - 1], AppendTo[a, x]], {x, 1, 1000}]; a
Select[Range[300], PrimeQ[#^3-#-1]&] (* Harvey P. Dale, Jul 22 2013 *)
PROG
(PARI) is(n)=isprime(n^3-n-1) \\ Charles R Greathouse IV, Apr 29 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 26 2006
STATUS
approved