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Least a(n) prime == 1 mod 6 such that q(n)*(q(n)+a(n))-1 is prime with q(i)=i-th prime == -1 mod 6.
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%I #5 Mar 31 2012 13:22:05

%S 7,7,13,13,13,13,13,31,31,19,31,7,19,7,43,7,7,13,13,7,13,61,43,7,31,

%T 37,37,13,151,19,13,13,7,67,13,7,19,13,7,13,43,73,43,19,13,67,43,13,

%U 13,7,7,13,31,73,19,7,31,43,31,67,7,31,37,13,31,7,37,7,103,43,13,13,19,13,43,7

%N Least a(n) prime == 1 mod 6 such that q(n)*(q(n)+a(n))-1 is prime with q(i)=i-th prime == -1 mod 6.

%H Pierre CAMI, <a href="/A143429/b143429.txt">Table of n, a(n) for n = 1..10000</a>

%e q(1)=5 5*(5+7)-1=59 prime so a(1)=7

%e q(2)=11 11*(11+7)=197 prime so a(2)=7

%Y Cf. A143427, A143428, A143430.

%K nonn

%O 1,1

%A _Pierre CAMI_, Aug 14 2008