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A072489 a(1) = 1, a(n) = a(n-1) times smallest divisor of n >= n^(1/2). 2

%I

%S 1,2,6,12,60,180,1260,5040,15120,75600,831600,3326400,43243200,

%T 302702400,1513512000,6054048000,102918816000,617512896000,

%U 11732745024000,58663725120000

%N a(1) = 1, a(n) = a(n-1) times smallest divisor of n >= n^(1/2).

%o Contribution from _Michael B. Porter_, Jan 30 2010: (Start)

%o (PARI) A033676(n) = {local(d);if(n<2,1,d=divisors(n);d[(length(d)+1)\2])}

%o A072489(n) = if(n<2,1,n*A072489(n-1)/A033676(n))

%o a=1;print(a);for(n=2,20,a=n*a/A033676(n);print(a)) (End)

%Y Cf. A072488.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Jul 13 2002

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Last modified November 17 07:44 EST 2018. Contains 317275 sequences. (Running on oeis4.)