A064030 - OEIS

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A064030

Product of unitary divisors of n!.

1, 2, 36, 576, 207360000, 268738560000, 416336312719673760153600000000, 6984964247141514123629140377600000000, 300679807141675805997423113304381849600000000

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OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..17

FORMULA

a(n)=(n!)^(A034444(n!)/2)

EXAMPLE

n = 6 has 8 unitary divisors:{16,45,9,80,5,144,1,720}, a(6) = 720^4 = 268738560000

MATHEMATICA

a[n_] := (n!)^(2^(PrimePi[n]-1)); Array[a, 10] (* Amiram Eldar, Jul 16 2019 *)

CROSSREFS

Cf. A048656, A048657, A061537, A061538, A000142.

Sequence in context: A025608 A230132 A141132 * A367982 A228790 A124104

Adjacent sequences: A064027 A064028 A064029 * A064031 A064032 A064033

KEYWORD

nonn

AUTHOR

Labos Elemer, Sep 13 2001

STATUS

approved