%I A136721
%S A136721 11,17,107,197,827,1487,1877,2087,3257,3467,5657,9437,13007,15647,15737,
%T A136721 16067,18047,18917,19427,21017,22277,25307,31727,34847,43787,51347,
%U A136721 55337,62987,67217,69497,72227,77267,79697,81047,82727,88817,97847
%N A136721 Prime quadruples: 3rd term.
%C A136721 Primes p such that p-6, p-4, and p+2 are prime. Apart from the first 
               term, a(n) = 17 (mod 30).
%C A136721 The members of each quadruple are twin primes when they are 1st and 2nd 
               terms and when 3rd and 4th terms. When they are 2nd and 3rd terms 
               they differ by 4.
%e A136721 The four terms in the first quadruple are 5,7,11,13 and in the 2nd 11,
               13,17,19. The four terms or members of each set must be simultaneously 
               prime.
%t A136721 lst={};Do[p0=Prime[n];If[PrimeQ[p2=p0+2], If[PrimeQ[p6=p0+6], If[PrimeQ[p8=p0+8], 
               AppendTo[lst, p6]]]], {n, 12^4}];lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), 
               Aug 22 2008]
%Y A136721 Cf. A007530 A090258 A136720.
%Y A136721 Sequence in context: A146036 A046122 A102870 this_sequence A107172 A090286 
               A056577
%Y A136721 Adjacent sequences: A136718 A136719 A136720 this_sequence A136722 A136723 
               A136724
%K A136721 easy,nonn
%O A136721 1,1
%A A136721 Enoch Haga (Enokh(AT)comcast.net), Jan 18 2008
%E A136721 Edited by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Oct 
               11 2009