A155703 Primes p such that 2*p^2 + 16*p + 23 is also prime.

3, 7, 13, 19, 31, 43, 97, 127, 223, 241, 271, 283, 307, 397, 421, 439, 577, 601, 619, 661, 673, 691, 727, 853, 859, 967, 1009, 1051, 1063, 1123, 1153, 1237, 1321, 1429, 1447, 1543, 1567, 1597, 1609, 1657, 1669, 1861, 1867, 1933, 1951, 1987, 2017, 2089, 2203

Offset: 1

Author

Vincenzo Librandi, Jan 25 2009

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A155702, A153037.

Programs

Magma

[p: p in PrimesUpTo(3000)|IsPrime(2*p^2+16*p+23)];

Mathematica

Select[Prime[Range[2500]], PrimeQ[(2*#^2 + 16*# + 23)]&] (* Vincenzo Librandi, Oct 30 2012 *)

Extensions

Entries confirmed by John W. Layman, Jun 17 2010