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a(n) is the product of the positive integers each of which is <= n and is divisible by exactly one prime dividing n (but is coprime to every other prime dividing n). (a(1) = 1).
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%I #17 Oct 01 2017 17:25:55

%S 1,2,3,8,5,24,7,384,162,1920,11,17280,13,322560,97200,10321920,17,

%T 58060800,19,1393459200,51438240,40874803200,23,536481792000,375000,

%U 25505877196800,7142567040,535623421132800,29,439378587648000,31

%N a(n) is the product of the positive integers each of which is <= n and is divisible by exactly one prime dividing n (but is coprime to every other prime dividing n). (a(1) = 1).

%H Michael De Vlieger, <a href="/A119794/b119794.txt">Table of n, a(n) for n = 1..807</a>

%e 12 is divisible by 2 and 3. The positive integers which are <= 12 and which are divisible by 2 or 3, but not by both 2 and 3, are: 2, 3, 4, 8, 9, 10. a(12) = the product of these integers, which is 17280.

%t Table[Times @@ Select[Range@ n, Function[k, Total@ Boole@ Map[Divisible[k, #] &, FactorInteger[n][[All, 1]]] == 1]], {n, 31}] (* _Michael De Vlieger_, Oct 01 2017 *)

%Y Cf. A116512, A119790, A120499.

%K nonn

%O 1,2

%A _Leroy Quet_, Jul 30 2006

%E Corrected and extended by _Joshua Zucker_, Aug 12 2006