A296507 Numbers m such that m^2 - 13 is a prime.

4, 6, 12, 18, 24, 30, 36, 54, 72, 84, 90, 96, 102, 114, 120, 138, 168, 186, 198, 204, 210, 216, 228, 240, 276, 294, 318, 330, 354, 360, 372, 378, 402, 414, 438, 444, 456, 480, 498, 504, 588, 600, 612, 618, 630, 636, 666, 678, 690, 714, 720, 726, 732, 738, 762

Offset: 1

Author

Zak Seidov, Dec 13 2017

Keywords

• nonn

Comments

All terms except 4 are divisible by 6. - Robert Israel, Dec 13 2017

Links

• Daniel Starodubtsev, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A028870, A028873, A028876, A028882, A090696.

Programs

Maple

select(n -> isprime(n^2-13), 2*[$2..10^4]); # Robert Israel, Dec 13 2017

Mathematica

Reap[m=4;Do[If[PrimeQ[m^2-13],Sow[m]];m=m+2,{1000}]][[2,1]]
Select[Range[800],PrimeQ[#^2-13]&] (* Harvey P. Dale, Mar 06 2023 *)

PARI

isok(n) = isprime(n^2-13); \\ Michel Marcus, Dec 14 2017