A322923 - OEIS

%I #17 Sep 08 2022 08:46:23

%S 13,19,37,43,61,73,97,127,163,181,223,241,271,307,313,331,397,421,457,

%T 523,541,547,577,601,673,691,727,757,811,853,883,937,997,1051,1063,

%U 1123,1153,1171,1231,1297,1303,1321,1531,1567,1627,1693,1783,1801

%N Primes of the form 3*p + 4, where p is a prime.

%H Muniru A Asiru, <a href="/A322923/b322923.txt">Table of n, a(n) for n = 1..10000</a>

%p select(isprime,[3*ithprime(p)+4$p=1..120]); # _Muniru A Asiru_, Mar 23 2019

%t Select[Table[p=Prime[n];3p+4,{n,85}],PrimeQ]

%o (Magma) [a: p in PrimesUpTo(600) | IsPrime(a) where a is 3*p+4];

%o (GAP) P:=Filtered([1..1000],IsPrime);;

%o a:=Filtered(List(P,i->3*i+4),k->IsPrime(k)); # _Muniru A Asiru_, Mar 23 2019

%o (PARI) terms(n) = my(x=0, i=0); forprime(p=1, , if(i >= n, break); x=3*p+4; if(ispseudoprime(x), print1(x, ", "); i++))

%o /* Print initial 50 terms as follows: */

%o terms(50) \\ _Felix Fröhlich_, Mar 23 2019

%Y Cf. A023209, A100202, A102851, A142120, A142262, A142817.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Mar 12 2019