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A130087
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Denominator of product{k=1 to n} k^mu(k), where mu is the Moebius function A008683.
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7
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1, 2, 6, 6, 30, 5, 35, 35, 35, 7, 77, 77, 1001, 143, 143, 143, 2431, 2431, 46189, 46189, 46189, 4199, 96577, 96577, 96577, 7429, 7429, 7429, 215441, 215441, 6678671, 6678671, 6678671, 392863, 392863, 392863, 14535931, 765049, 765049, 765049
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OFFSET
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1,2
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COMMENTS
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a(n) is also the denominator of H(n)^2 * n! for all n < 897, where H(n) = 1 + 1/2 + ... + 1/n is the n-th harmonic number. - John M. Campbell, May 13 2011
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LINKS
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MAPLE
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with(numtheory): a:=n->denom(product(k^mobius(k), k=1..n)): seq(a(n), n=1..50); # Emeric Deutsch, May 11 2007
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MATHEMATICA
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Table[Denominator[HarmonicNumber[n]^2*(n!)], {n, 200}]
(* Second program: *)
With[{s = Array[#^MoebiusMu@ # &, 39]}, Denominator@ Table[Times @@ Take[s, n], {n, Length@ s}]] (* Michael De Vlieger, Sep 20 2017 *)
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PROG
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CROSSREFS
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KEYWORD
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frac,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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