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%I #7 Sep 08 2022 08:46:11
%S 3,71,79,89,101,199,271,281,293,349,359,433,463,479,569,577,641,659,
%T 701,743,769,787,809,839,863,911,953,1013,1033,1049,1109,1181,1249,
%U 1277,1321,1361,1399,1429,1451,1459,1481,1511,1549,1571,1627,1693,1733,1759,1889
%N Primes prime(n) such that prime(n) + 7*n is also prime.
%e prime(2)=3 is in the sequence because 3+7*2 = 17 is prime.
%e prime(20)=71 is in the sequence because 71+7*20 = 211 is prime.
%t Prime[Select[Range[300], PrimeQ[Prime[#] + 7# ]&]]
%o (Magma) [NthPrime(n): n in [1..300] | IsPrime(NthPrime(n)+7*n)];
%Y Cf. A061067, A231232, A231383, A254462.
%K nonn
%O 1,1
%A _Vincenzo Librandi_, Feb 04 2015
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