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Primes prime(n) such that prime(n) + 4*n is also prime.
2

%I #7 Sep 08 2022 08:46:11

%S 3,5,7,11,13,23,47,59,71,73,79,97,103,113,127,137,181,199,251,263,271,

%T 281,293,331,359,367,397,419,433,443,449,457,463,487,503,523,541,571,

%U 607,613,617,631,653,709,719,751,761,773,829,839,877,881,953,967,971

%N Primes prime(n) such that prime(n) + 4*n is also prime.

%H Vincenzo Librandi, <a href="/A254673/b254673.txt">Table of n, a(n) for n = 1..1000</a>

%e prime(4)=7 is in the sequence because 7+4*4 = 23 is prime.

%e prime(6)=13 is in the sequence because 13+4*6 = 37 is prime.

%t Prime[Select[Range[180], PrimeQ[Prime[#] + 4 #] &]]

%o (Magma) [NthPrime(n): n in [1..200] | IsPrime(NthPrime(n)+4*n)]

%Y Cf. A061067, A231232, A231383, A254462, A254665, A254672.

%K nonn

%O 1,1

%A _Vincenzo Librandi_, Feb 05 2015