OFFSET
1,1
EXAMPLE
2 is in the sequence because 2^8 + 1 = 257 and 4^8 + 1 = 65537 are both prime.
4 is not in the sequence because although 4^8 + 1 is a prime (as we saw above), 6^8 + 1 is not, being a multiple of 17.
MATHEMATICA
lst = {}; Do[p = n^8 + 1; q = (n + 2)^8 + 1; If[PrimeQ[p] && PrimeQ[q], AppendTo[lst, n]], {n, 0, 21000}]; lst (* Lagneau *)
Select[Range[10^5], PrimeQ[#^8 + 1] && PrimeQ[(# + 2)^8 + 1] &] (* Alonso del Arte, Oct 17 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Michel Lagneau, Oct 17 2012
STATUS
approved