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%I A242772 #18 Dec 31 2019 08:21:23
%S A242772 5,11489,32969,33329,33599,42839,58109,93809,96329,114599,180179,
%T A242772 272999,309539,334889,401309,540539,633569,717089,784349,820409,
%U A242772 870239,879689,907139,948089,989249,991619,994559,1020959,1028579,1044749,1185659,1189649,1245449,1253909
%N A242772 The lesser of twin primes p1 such that 2*p1 + p2 is a prime number (A174913) and also the lesser of other twin primes in A174913.
%C A242772 It seems that a(n) == 9 mod 10 for n > 1.
%C A242772 a(n) == 9 (mod 10) for n > 1 since if p1 == 1, 3 or 7 (mod 10) then 2*p1 + p2, p2, or 2*p1 + p2 + 2 is divisible by 5, respectively. - _Amiram Eldar_, Dec 31 2019
%H A242772 Amiram Eldar, <a href="/A242772/b242772.txt">Table of n, a(n) for n = 1..10000</a>
%e A242772 a(1) = A174913(2) = 5 and 2*5 + 7 = 17 = A174913(3).
%t A242772 Select[Range[10^6], And @@ PrimeQ[{#, # + 2,(p = 3*# + 2), p + 2, 3*p + 2}] &] (* _Amiram Eldar_, Dec 31 2019 *)
%o A242772 (PARI) isok(p) = isprime(p) && isprime(p+2) && isprime(q=3*p+2) && isprime(q+2) && isprime(3*q+2); \\ _Michel Marcus_, May 23 2014
%Y A242772 Cf. A001359, A174913, A174920, A242773.
%K A242772 nonn
%O A242772 1,1
%A A242772 _Ivan N. Ianakiev_, May 22 2014

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