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%I #9 Aug 03 2014 14:01:32
%S 6,15,91,65,341,91,1247,697,703,341,1541,481,4187,1247,1891,1649,
%T 14111,703,43739,2501,5461,1541,6533,7081,15251,4187,17767,3277,13747,
%U 1891,116003,18721,13333,14111,14981,2701,33227,43739,12403,9881,61337,5461,74563
%N Smallest product of two distinct primes of the form n*k+1.
%e a(1) = 2*3 = 6
%e a(2) = 3*5 = 15
%e a(3) = 7*13 = 91
%e a(4) = 5*13 = 65
%e a(5) = 11*31 = 341
%t Table[ps = Select[Table[n*k + 1, {k, 100}], PrimeQ, 2]; If[Length[ps] == 2, ps[[1]]*ps[[2]], 0], {n, 100}] (* _T. D. Noe_, Oct 21 2011 *)
%Y Cf. A193869, A193879.
%K nonn
%O 1,1
%A _Omar E. Pol_, Sep 03 2011