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Product of composite numbers in range n+1 to 2n, exclusive of endpoints.
1

%I #9 Sep 14 2018 13:34:14

%S 1,1,1,6,72,720,1080,25200,40320,725760,25401600,558835200,

%T 23950080000,1120863744000,1961511552000,58845346560000,

%U 3452260331520000,4108189794508800000,7394741630115840000,521857480753889280000,948831783188889600000,39850934893933363200000,3287702128749502464000000

%N Product of composite numbers in range n+1 to 2n, exclusive of endpoints.

%H Harvey P. Dale, <a href="/A238103/b238103.txt">Table of n, a(n) for n = 1..423</a>

%e For n=6, the range (7,12) contains three composite numbers 8,9,10 whose product is a(6) = 720.

%t Table[Times@@Select[Range[n+2,2n-1],CompositeQ],{n,30}] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 14 2018 *)

%Y Cf. A157625 (inclusive version).

%K nonn

%O 1,4

%A _N. J. A. Sloane_, Feb 26 2014