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%I #10 Mar 12 2019 20:46:44
%S 3,4,1,2,1,4,2,1,1,2,3,2,1,1,3,2,2,3,2,1,1,5,4,1,1,7,2,2,5,3,3,1,1,1,
%T 3,4,1,1,3,3,5,2,2,3,1,2,2,1,6,1,4,4,4,1,2,1,1,5,2,2,1,3,4,1,5,2,3,1,
%U 5,2,2,2,1,5,3,1,2,3,2,2,1,3,10,1,1,1,3,2,5,1,2,1,1,1,4,3,6,3,3,2,2,2,4,2,1
%N Smallest k such that kn+1 is a semiprime.
%C Conjecture: for every n > 2 there exists a number k < n such that n*k + 1 is a semiprime.
%H T. D. Noe, <a href="/A085710/b085710.txt">Table of n, a(n) for n=1..1000</a>
%t sk[n_]:=Module[{k=1},While[PrimeOmega[k*n+1]!=2,k++];k]; Array[sk,120] (* _Harvey P. Dale_, Mar 12 2019 *)
%Y Cf. A001358.
%K easy,nonn
%O 1,1
%A _Jason Earls_, Jul 19 2003
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