%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