A274505 - OEIS

%I #19 Sep 08 2022 08:46:17

%S 7,11,17,19,23,31,47,61,67,89,101,107,109,137,151,163,199,283,347,353,

%T 373,397,401,409,431,439,457,479,487,523,577,607,619,641,647,661,691,

%U 761,787,809,907,929,1033,1087,1103,1153,1201,1229,1307,1319

%N Primes p such that 3*p-10 and 3*p+10 are prime numbers.

%C Intersection of A023211 and A230227.

%H Vincenzo Librandi, <a href="/A274505/b274505.txt">Table of n, a(n) for n = 1..1000</a>

%e 7 is a term because 3*7-10 = 11 and 3*7+10 = 31 are primes.

%t Select[Prime[Range[400]], PrimeQ[3 # - 10] && PrimeQ[3 # + 10] &]

%o (Magma) [p: p in PrimesUpTo(1500) |IsPrime(3*p-10) and IsPrime(3*p+10)];

%Y Cf. A023211, A164568, A230227.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jun 30 2016