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%I #5 Mar 31 2017 16:53:59
%S 1,3,1,3,2,4,13,5,9,10,6,8,61,121,3,13,17,79,45,27,120,145,113,11,41,
%T 198,102,139,202,103,23,48,177,43,486,169,501,251,106,132,40,155,1890,
%U 116,584,107,629,241,1331,2078,562,57,52,71,567,73,262,332,483,419,423
%N Least k such that k*(p(n+1)#-p(n)#)-1 and k*(p(n+1)#-p(n)#)+1 are twin primes.
%H Harvey P. Dale, <a href="/A126088/b126088.txt">Table of n, a(n) for n = 1..200</a>
%e 3*(2*3*5-2*3)-1=71 3*(2*3*5-2*3)+1=73; 71 and 73 twin primes so k(2)=3
%t ktp[n_]:=Module[{k=1},While[!PrimeQ[k*n-1]||!PrimeQ[k*n+1],k++];k]; With[ {prmrls=#[[2]]-#[[1]]&/@Partition[FoldList[Times,Prime[Range[ 70]]],2,1]}, ktp/@prmrls] (* _Harvey P. Dale_, Mar 31 2017 *)
%K nonn
%O 1,2
%A _Pierre CAMI_, Mar 03 2007
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