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A071351
Numbers n such that both n^4 + 2 and n^4 - 2 are prime.
2
3, 21, 87, 99, 129, 141, 279, 627, 657, 777, 783, 795, 1653, 1725, 1833, 1959, 2001, 2043, 3039, 3399, 3609, 3861, 3975, 4257, 4371, 4491, 5403, 5541, 5709, 5985, 7371, 7539, 7869, 7917, 8397, 8445, 8547, 8793, 9051, 9057, 9915, 9933, 11067, 12153
OFFSET
1,1
LINKS
EXAMPLE
n=3: n^4 = 81; {79,83} are primes.
MATHEMATICA
lst={}; Do[p1=n^4-2; p2=n^4+2; If[PrimeQ[p1]&&PrimeQ[p2], AppendTo[lst, n]], {n, 0, 8!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 17 2009 *)
Select[Range[730000], AllTrue[#^4 + {2, -2}, PrimeQ] &] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 02 2018 *)
KEYWORD
easy,nonn
AUTHOR
Labos Elemer, May 21 2002
STATUS
approved