A063910 Primes p such that 2*p - 7 is also prime.

5, 7, 13, 19, 37, 43, 67, 73, 79, 103, 109, 139, 157, 193, 223, 277, 307, 313, 349, 367, 373, 379, 397, 409, 433, 457, 463, 487, 499, 523, 547, 619, 643, 727, 733, 739, 769, 787, 853, 877, 883, 919, 937, 997, 1009, 1069, 1093, 1123, 1129, 1237

Offset

1,1

Comments

All terms > 5 are == 1 (mod 6). - Zak Seidov, Jan 07 2014

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Formula

A089192 INTERSECT A000040. - R. J. Mathar, Mar 23 2017

Mathematica

Select[Prime[Range[2, 2000]], PrimeQ[2 # - 7]&] (* Vincenzo Librandi, Feb 02 2014 *)

Prog

(PARI) { n=0; p=1; for (m=1, 10^9, p=nextprime(p+1); if (isprime(2*p - 7), write("b063910.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 02 2009
(Magma) [n: n in [3..2000] | IsPrime(n) and IsPrime(2*n-7)]; // Vincenzo Librandi, Feb 02 2014

Crossrefs

Sequence in context: A297674 A072677 A117249 * A288632 A189557 A045444

Adjacent sequences: A063907 A063908 A063909 * A063911 A063912 A063913

Keyword

easy,nonn

Author

N. J. A. Sloane, Aug 31 2001

Status

approved