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A050374 Number of ordered factorizations of n into composite factors. 0
1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 2, 0, 1, 0, 1, 1, 1, 0, 3, 1, 1, 1, 1, 0, 1, 0, 3, 1, 1, 1, 4, 0, 1, 1, 3, 0, 1, 0, 1, 1, 1, 0, 5, 1, 1, 1, 1, 0, 3, 1, 3, 1, 1, 0, 5, 0, 1, 1, 5, 1, 1, 0, 1, 1, 1, 0, 7, 0, 1, 1, 1, 1, 1, 0, 5, 2, 1, 0, 5, 1, 1, 1, 3, 0, 5, 1, 1, 1, 1, 1, 10, 0, 1, 1, 4, 0, 1 (list; graph; refs; listen; history; internal format)
OFFSET

1,16

COMMENTS

a(n) depends only on prime signature of n (cf. A025487). So a(24) = a(375) since 24=2^3*3 and 375=3*5^3 both have prime signature (3,1).

The Dirichlet inverse is given by A005171, all but the first term in A005171 turned negative. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 15 2010]

FORMULA

Dirichlet g.f.: 1/(1-B(s)) where B(s) is d.g.f. of characteristic function of composite numbers.

CROSSREFS

Cf. A002033, A002808, A050370-A050375. a(p^k)=A000045(n-1). a(A002110)=A032032.

Sequence in context: A147768 A167746 A050370 * A047886 A014944 A015879

Adjacent sequences:  A050371 A050372 A050373 * A050375 A050376 A050377

KEYWORD

nonn

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Nov 15 1999.

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Last modified February 15 08:49 EST 2012. Contains 205740 sequences.