A092057 Primes of the form 2*p^2 - 1, where p is prime.

7, 17, 97, 241, 337, 577, 3361, 3697, 6961, 10657, 23761, 25537, 32257, 37537, 49297, 64081, 65521, 77617, 79201, 89041, 126001, 138337, 153457, 171697, 193441, 249217, 269377, 287281, 334561, 351121, 374977, 474337, 633937, 652081, 665857

Offset: 1

Author

Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Feb 19 2004

Keywords

• easy
• nonn

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A092058.

Cf. A106483 (primes p such that 2p^2 - 1 is also prime).

Programs

Mathematica

lst={};Do[p=Prime[n];If[PrimeQ[r=2*p^2-1],AppendTo[lst,r]],{n,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Jun 20 2009 *)
Select[2#^2-1&/@Prime[Range[200]],PrimeQ] (* Harvey P. Dale, Jun 26 2017 *)

PARI

for (i=1,300,if(isprime(2*prime(i)^2-1),print1(2*prime(i)^2-1,",")))