A153975 Values of n such that n^2-3 and n^2+3 are both prime.

4, 8, 10, 14, 64, 92, 112, 140, 146, 172, 218, 298, 304, 322, 326, 340, 350, 356, 416, 440, 470, 508, 554, 560, 580, 626, 634, 652, 668, 686, 694, 704, 728, 736, 746, 770, 806, 818, 868, 892, 920, 1054, 1082, 1102, 1130, 1156, 1196, 1256, 1264, 1378, 1418

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jan 03 2009

Keywords

• nonn
• easy

Comments

Intersection of A028873 and A049422. - Zak Seidov, Oct 12 2014

Examples

			4^2 - 3 = 13 and 4^2 + 3 = 19 are both primes, so 4 is in the sequence.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A028870, A028873, A038599, A049422, A108701, A153974.

Programs

Magma

[n: n in [1..1400] | IsPrime(n^2-3) and IsPrime(n^2+3)]; // Vincenzo Librandi, Oct 12 2014

Mathematica

Select[Range[1500], PrimeQ[#^2 - 3] && PrimeQ[#^2 + 3] &] (* Vincenzo Librandi, Oct 12 2014 *)

PARI

is(n) = isprime(n^2-3) && isprime(n^2+3); \\ Altug Alkan, Sep 01 2016

Extensions

Incorrect term 0 removed and Mma edited by Zak Seidov, Oct 12 2014