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%I #8 Jul 23 2012 12:18:36
%S 2,4,1,2,2,4,1,4,2,8,1,2,4,28,2,11,2,4,1,4,2,32,1,3,4,40,2,14,2,4,1,
%T 37,6,138,1,2,10,40,2,5,2,16,1,16,2,26,3,4,4,10,2,20,4,10,1,7,2,50,1,
%U 2,10,22,3,6,2,6,3,69,2,8,1,2,4,40,5,20,2,4,1,7,2,20,1,8,4,10,2,32,4,12,1,13
%N Table of the smallest (x,y) pairs such that x*n+1 is prime, y*n+1 is a larger prime, and (x*n+1)*(y*n+1)-2 is also prime.
%C The associated (x*n+1)*(y*n+1) for a solution is a semiprime, so the (x*n+1)*(y*n+1)-2 are actually Chen primes.
%C If more than one pair exists for a given n, priority is given to minimize x, the smaller prime.
%e For n=3, (x,y)=(2,4), 2*3+1=7 is prime, 4*3+1=13 is prime, and 7*13-2=89 is a Chen prime.
%e 2,4;
%e 1,2;
%e 2,4;
%e 1,4;
%e 2,8;
%e 1,2;
%e 4,28;
%e 2,11;
%e 2,4;
%e 1,4;
%e 2,32;
%e 1,3;
%e 4,40;...
%Y Cf. A112230.
%K nonn,tabf
%O 1,1
%A _Pierre CAMI_, Aug 29 2005
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