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A216152 A205957(n) where n is a nonprime number. 2
1, 2, 12, 48, 144, 1440, 34560, 483840, 7257600, 58060800, 3135283200, 125411328000, 2633637888000, 57940033536000, 5562243219456000, 27811216097280000, 723091618529280000, 6507824566763520000, 364438175738757120000, 327994358164881408000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The distinct values of A205957. Partial products of A216153.

a(1),...,a(10) are highly totient numbers (A097942) and products of distinct factorials (A058295). The author conjectures that this is true in general.

LINKS

Table of n, a(n) for n=1..20.

Peter Luschny, The von Mangoldt Transformation.

FORMULA

a(n) = A205957(A018252(n)).

MATHEMATICA

A205957[n_] := Exp[-Sum[MoebiusMu[p] Log[k/p], {k, 1, n}, {p, FactorInteger[k][[All, 1]]}]];

Table[A205957[n], {n, 0, 30}] // DeleteDuplicates (* Jean-Fran├žois Alcover, Jul 08 2019 *)

PROG

(Sage)

# sorted(list(set([A205957(n) for n in (0..31)])))

def A216152_list(n) :

    C = filter(lambda k: not is_prime(k), (1..n))

    return [A205957(c) for c in C]

A216152_list(31)

CROSSREFS

Cf. A051451.

Sequence in context: A320684 A069946 A176684 * A048501 A001815 A333728

Adjacent sequences:  A216149 A216150 A216151 * A216153 A216154 A216155

KEYWORD

nonn

AUTHOR

Peter Luschny, Sep 02 2012

STATUS

approved

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Last modified August 3 22:03 EDT 2021. Contains 346441 sequences. (Running on oeis4.)