login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Primes p such that 3p + 4 and 4p + 3 are primes.
2

%I #17 Sep 08 2022 08:45:17

%S 5,11,19,31,41,59,89,109,151,179,181,229,241,331,349,389,439,509,521,

%T 599,661,719,769,839,881,929,1019,1039,1129,1229,1291,1409,1451,1481,

%U 1549,1669,1741,1759,1801,1811,2111,2131,2539,2621,2671,2699,2819,2879

%N Primes p such that 3p + 4 and 4p + 3 are primes.

%C Prime terms in A124855.

%H Marius A. Burtea, <a href="/A106068/b106068.txt">Table of n, a(n) for n = 1..534</a>

%t Select[Prime[Range[450]], PrimeQ[4#+3]&&PrimeQ[3#+4]&]

%o (Magma) [p: p in PrimesUpTo(5000)|IsPrime(3*p+4) and IsPrime(4*p+3)] // _Vincenzo Librandi_, Jan 30 2011

%o (PARI) isok(p) = isprime(p) && isprime(3*p+4) && isprime(4*p+3); \\ _Michel Marcus_, Oct 12 2018

%Y Cf. A034936, A095278, A124855.

%K nonn

%O 1,1

%A _Zak Seidov_, May 07 2005

%E Extended by _Ray Chandler_, Mar 14 2007