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A280821
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Partial products of A001783.
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1
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1, 1, 2, 6, 144, 720, 518400, 54432000, 121927680000, 23044331520000, 83623270219776000000, 32194959034613760000000, 15421436889514446422016000000000, 297710839152076388177018880000000000, 267015660792140704250415525396480000000000
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OFFSET
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1,3
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COMMENTS
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A001783(n) = the product of totatives of n.
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LINKS
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FORMULA
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a(n) = Product_{i=1..n} A001783(i).
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MATHEMATICA
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FoldList[#1 #2 &, Table[Times @@ Select[Range@ n, CoprimeQ[n, #] &], {n, 15}]] (* Michael De Vlieger, Jan 11 2017 *)
SetAttributes[Phitorial, {Listable}]
Phitorial[n_]:=n^EulerPhi[n]*Times@@((Factorial[#]/#^#)^MoebiusMu[n/#]&/@Divisors[n])
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PROG
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(Magma) [&*[&*[h: h in [1..k] | GCD(h, k) eq 1]: k in [1..n]]: n in [1..100]]
(PARI) f(n) = prod(k=2, n-1, k^(gcd(k, n)==1)); \\ A001783
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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