A254665 Primes prime(n) such that prime(n) + 7*n is also prime.

3, 71, 79, 89, 101, 199, 271, 281, 293, 349, 359, 433, 463, 479, 569, 577, 641, 659, 701, 743, 769, 787, 809, 839, 863, 911, 953, 1013, 1033, 1049, 1109, 1181, 1249, 1277, 1321, 1361, 1399, 1429, 1451, 1459, 1481, 1511, 1549, 1571, 1627, 1693, 1733, 1759, 1889

Offset: 1

Author

Vincenzo Librandi, Feb 04 2015

Keywords

• nonn

Examples

			prime(2)=3 is in the sequence because 3+7*2 = 17 is prime.
prime(20)=71 is in the sequence because 71+7*20 = 211 is prime.
		

Crossrefs

Cf. A061067, A231232, A231383, A254462.

Programs

Magma

[NthPrime(n): n in [1..300] | IsPrime(NthPrime(n)+7*n)];

Mathematica

Prime[Select[Range[300], PrimeQ[Prime[#] + 7# ]&]]