A106087 Primes p such that 7*p+4 and 4*p+7 are primes.

19, 61, 139, 271, 379, 601, 631, 709, 751, 769, 829, 1021, 1069, 1129, 1249, 1291, 1549, 1579, 1621, 1699, 1801, 1831, 2029, 2089, 2251, 2671, 2719, 2791, 2851, 3001, 3049, 3079, 3121, 3259, 3331, 3361, 3559, 3691, 3769, 3919, 4021, 4201, 4219, 4591

Offset

1,1

Links

Table of n, a(n) for n=1..44.

Mathematica

Select[Prime[Range[220]], PrimeQ[4#+7]&&PrimeQ[7#+4]&]

Prog

(Magma) [p: p in PrimesUpTo(10000)| IsPrime(7*p+4) and IsPrime(4*p+7)] /* Vincenzo Librandi, Nov 13 2010 */

Crossrefs

Sequence in context: A338299 A092327 A139498 * A341081 A201812 A262317

Adjacent sequences: A106084 A106085 A106086 * A106088 A106089 A106090

Keyword

nonn

Author

Zak Seidov, May 07 2005

Extensions

More terms from Vincenzo Librandi, Apr 01 2010

Status

approved