A106086 Primes p such that 7*p + 2 and 2*p + 7 are primes.

3, 5, 11, 23, 47, 53, 71, 131, 173, 197, 251, 257, 293, 317, 383, 461, 467, 587, 593, 683, 701, 773, 797, 863, 953, 983, 1031, 1103, 1151, 1187, 1193, 1217, 1301, 1307, 1373, 1451, 1481, 1607, 1721, 1787, 2111, 2207, 2237, 2333, 2633, 2903, 3023, 3221, 3347

Offset: 1

Author

Zak Seidov, May 07 2005

Keywords

• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A105760 (2n+7 is prime), A105772 (7n+2 is prime).

Cf. A107438, A023206.

Programs

Magma

[p: p in PrimesUpTo(5000)|IsPrime(7*p+2) and IsPrime(2*p+7)] // Vincenzo Librandi, Jan 30 2011

Mathematica

Select[Prime[Range[220]], PrimeQ[2#+7]&&PrimeQ[7#+2]&]

Extensions

More terms from Rick L. Shepherd, Jan 29 2006