A181848 - OEIS

%I #35 Apr 10 2017 06:06:26

%S 3,5,13,59,103,113,223,241,269,337,491,773,787,823,911,919,1571,1637,

%T 1723,1879,1949,2089,2423,2521,2753,2953,2971,2999,3011,3137,3361,

%U 3571,3739,4231,4363,4663,4909,5791,5903,6221,6359,6793,7043,7507,7873,9323,9403

%N Consider two consecutive primes {p,q} such that P=2p+q and Q=2q+p are both prime. Sequence gives lesser primes p.

%C Note that Q-P=q-p and {P,Q} are not necessarily consecutive primes.

%H Zak Seidov, <a href="/A181848/b181848.txt">Table of n, a(n) for n = 1..3000</a>

%e a(1)=3 because p=3, q=5 and P=11 and Q=13 are both prime

%e a(3)=13 because p=13, q=17 and P=43 and Q=47 are both prime.

%t a=2;Reap[Do[b=Prime[n];If[PrimeQ[2*a+b]&&PrimeQ[2*b+a],Sow[a]];a=b,{n,2,200}]][[2,1]]

%o (PARI) isok(p) = isprime(p) && (q=nextprime(p+1)) && isprime(p+2*q) && isprime(q+2*p); \\ _Michel Marcus_, Mar 05 2016

%Y Intersection of A173971 and A175914. - _Zak Seidov_, Mar 04 2016

%K nonn

%O 1,1

%A _Zak Seidov_, Aug 18 2012