A182583 Primes p such that (5p^2-1)/4 is also prime.

3, 5, 7, 11, 13, 23, 29, 31, 43, 53, 61, 71, 73, 89, 109, 127, 139, 149, 163, 229, 257, 263, 271, 277, 307, 331, 337, 383, 389, 419, 433, 449, 457, 463, 479, 523, 541, 607, 631, 643, 647, 653, 661, 673, 691, 727, 761, 769, 797, 809, 821, 823, 829, 859, 881

Offset: 1

Author

Zak Seidov, May 06 2012

Keywords

• nonn

Links

• Zak Seidov, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A104012.

Programs

Mathematica

Select[Prime[Range[200]], PrimeQ[(5*#^2 - 1)/4] &]  (* T. D. Noe, May 07 2012 *)

Formula

a(n) = 2*A104012(n) + 1.