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%I #13 Nov 21 2013 12:50:20
%S 1,3,3,3,15,15,105,105,105,105,105,105,1155,1155,1155,15015,15015,
%T 15015,15015,15015,15015,255255,255255,255255,4849845,4849845,4849845,
%U 4849845,4849845,4849845,111546435,111546435,111546435,111546435,111546435,111546435
%N Half of greatest common divisor of products of first n prime numbers and first n composite numbers.
%C a(n) = gcd(A002110(n),A036691(n)) / 2.
%H Reinhard Zumkeller, <a href="/A196529/b196529.txt">Table of n, a(n) for n = 1..1000</a>
%e a(3) = gcd(2*3*5,4*6*8)/2 = gcd(30,192)/2 = 6/2 = 3;
%e a(4) = gcd(2*3*5*7,4*6*8*9)/2 = gcd(210,1728)/2 = 6/2 = 3;
%e a(5) = gcd(2*3*5*7*11,4*6*8*9*10)/2 = gcd(2310,17280)/2 = 30/2 = 15.
%t nn=40;With[{prs=Prime[Range[nn]],comps=Take[Complement[Range[Prime[nn]], Prime[ Range[nn]]],nn]},Rest[Table[GCD[Times@@Take[prs,n], Times@@Take[ comps,n]]/2,{n,nn}]]] (* _Harvey P. Dale_, Oct 16 2011 *)
%Y Cf. A196527, A070826.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Oct 03 2011
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