A144561 Prime p such that p^2+13p+23 is prime.

2, 3, 5, 7, 19, 37, 41, 47, 59, 71, 73, 103, 157, 163, 211, 227, 229, 239, 283, 293, 311, 313, 337, 353, 359, 367, 419, 443, 463, 499, 521, 523, 577, 619, 643, 647, 653, 661, 733, 751, 787, 839, 853, 863, 877, 883, 929, 1021, 1069, 1087, 1123, 1129, 1163

Offset: 1

Author

Vincenzo Librandi, Jan 03 2009

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A153781.

Programs

Magma

[p: p in PrimesUpTo(1500) | IsPrime(p^2+13*p+23)] // Vincenzo Librandi, Aug 30 2012

Maple

a := proc (n) if isprime(n) = true and isprime(n^2+13*n+23) = true then n else end if end proc: seq(a(n), n = 2 .. 1300); # Emeric Deutsch, Jan 20 2009

Mathematica

Select[Prime[Range[200]], PrimeQ[#^2 + 13 # + 23] &] (* Vincenzo Librandi, Aug 30 2012 *)

PARI

isok(p) = isprime(p) && isprime(p^2+13*p+23); \\ Michel Marcus, Feb 10 2018

Extensions

Extended by Emeric Deutsch, Jan 20 2009