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A072048 Number of divisors of the squarefree numbers: tau(A005117(n)). 3
1, 2, 2, 2, 4, 2, 4, 2, 2, 4, 4, 2, 2, 4, 4, 2, 4, 2, 8, 2, 4, 4, 4, 2, 4, 4, 2, 8, 2, 4, 2, 4, 2, 4, 4, 4, 2, 2, 4, 4, 8, 2, 4, 8, 2, 2, 4, 4, 8, 2, 4, 2, 4, 4, 4, 2, 4, 4, 4, 4, 2, 2, 8, 2, 8, 4, 2, 2, 8, 4, 2, 8, 4, 4, 4, 4, 4, 2, 4, 8, 2, 4, 4, 2, 8, 2, 4, 4, 4, 4, 4, 2, 2, 8, 4, 2 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

a(n) = 2^A072047(n) = 2^A001221(A005117(n)).

Also the number of cube-free numbers with the same squarefree kernel as the n-th squarefree number, see A073245.

CROSSREFS

a(n) = A000005(A005117(n)), A062822.

Sequence in context: A108920 A079405 A201353 * A161841 A152674 A072056

Adjacent sequences:  A072045 A072046 A072047 * A072049 A072050 A072051

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 09 2002

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Last modified February 17 10:05 EST 2012. Contains 206009 sequences.