A153120 Primes p such that p^2 +- 42 are also primes.

5, 11, 13, 23, 53, 89, 101, 103, 109, 181, 197, 307, 313, 457, 467, 571, 691, 769, 863, 907, 1061, 1087, 1223, 1453, 1487, 1607, 1913, 2129, 2161, 2311, 2729, 2741, 2767, 2917, 3313, 3343, 3359, 3433, 4363, 4373, 4547, 4703, 4783, 4787, 4877, 5119, 5237

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

fQ[n_]:=PrimeQ[n^2-42]&&PrimeQ[n^2+42]; lst={}; Do[If[fQ@Prime[n], AppendTo[lst, Prime[n]]], {n, 7!}]; lst
Select[Prime[Range[6000]], PrimeQ[#^2 - 42]&&PrimeQ[#^2 + 42]&] (* Vincenzo Librandi, Apr 08 2013 *)

Prog

(Magma) [p: p in PrimesUpTo(6000) | IsPrime(p^2-42) and IsPrime(p^2+42)]; // Vincenzo Librandi, Apr 08 2013

Crossrefs

Cf. A153116, A153119.

Sequence in context: A079732 A309158 A161540 * A115782 A051654 A225754

Adjacent sequences: A153117 A153118 A153119 * A153121 A153122 A153123

Keyword

nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, Dec 18 2008

Status

approved