cp's OEIS Frontend

A138697 Primes p such that 42*p-1, 42*p+1 and 48*p-1, 48*p+1 are twin primes.

%I A138697 #13 Sep 08 2022 08:45:33
%S A138697 31,331,2971,4421,4861,5309,5441,20431,22381,23459,28151,33911,37061,
%T A138697 37699,47491,66449,75821,82799,83701,86131,91961,106621,110059,112289,
%U A138697 130811,134669,135461,141601,144461,152959,153701,167311,167759,171049
%N A138697 Primes p such that 42*p-1, 42*p+1 and 48*p-1, 48*p+1 are twin primes.
%H A138697 Vincenzo Librandi, <a href="/A138697/b138697.txt">Table of n, a(n) for n = 1..2000</a>
%e A138697 42*31-1=1301, 42*31+1=1303; 48*31-1=1487, 48*31+1=1489; ...
%t A138697 a=42;b=48;Select[Prime[Range[14^4]],PrimeQ[a*#-1]&&PrimeQ[a*#+1]&&PrimeQ[b*#-1]&&PrimeQ[b*#+1]&]
%o A138697 (Magma) [p: p in PrimesUpTo(1000)| IsPrime(42*p-1) and IsPrime(42*p+1) and IsPrime(48*p-1) and IsPrime(48*p+1)]; // _Vincenzo Librandi_, Nov 24 2010
%K A138697 nonn,easy
%O A138697 1,1
%A A138697 _Vladimir Joseph Stephan Orlovsky_, May 15 2008
%E A138697 More terms from _Vincenzo Librandi_, Apr 01 2010