OFFSET
1,1
COMMENTS
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
2^3 - 2^2 - 1 = 3, 2^3 - 2^2 + 1 = 5, 3 and 5 are twin primes, so 2 is in the sequence.
MATHEMATICA
lst={}; Do[If[PrimeQ[n^3-n^2-1]&&PrimeQ[n^3-n^2+1], AppendTo[lst, n]], {n, 10^3}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 08 2008 *)
tpQ[n_]:=Module[{c=n^3-n^2}, And@@PrimeQ[{c+1, c-1}]]; Select[Range[ 1700], tpQ] (* Harvey P. Dale, Aug 27 2012 *)
PROG
(Magma) [n: n in [0..100000] |IsPrime(n^3-n^2-1) and IsPrime(n^3-n^2+1)]; // Vincenzo Librandi, Nov 13 2010
(PARI) isok(n) = isprime(n^3 - n^2 - 1) && isprime(n^3 - n^2 + 1); \\ Michel Marcus, Aug 24 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Nov 16 2005
STATUS
approved