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A092520
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Number of square divisors of n-th cube.
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0
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1, 2, 2, 4, 2, 4, 2, 5, 4, 4, 2, 8, 2, 4, 4, 7, 2, 8, 2, 8, 4, 4, 2, 10, 4, 4, 5, 8, 2, 8, 2, 8, 4, 4, 4, 16, 2, 4, 4, 10, 2, 8, 2, 8, 8, 4, 2, 14, 4, 8, 4, 8, 2, 10, 4, 10, 4, 4, 2, 16, 2, 4, 8, 10, 4, 8, 2, 8, 4, 8, 2, 20, 2, 4, 8, 8, 4, 8, 2, 14, 7, 4, 2, 16, 4, 4, 4, 10, 2, 16, 4, 8, 4, 4, 4, 16
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| a(n) = A000005(n) iff n is squarefree.
Apparently the inverse Mobius transform of A056624 (and therefore multiplicative). - R. J. Mathar, Feb 07 2011
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EXAMPLE
| n=12, the divisors of 12^3=1728 are 1=1^2, 2, 3, 4=2^2, 6, 8,
9=3^2, 12, 16=4^2, 18, 24, 27, 32, 36=6^2, 48, 54, 64=8^2, 72, 96, 108,
144=12^2, 192, 216, 288, 432, 576=24^2, 864 and 1728: eight of them are
squares, therefore a(12)=8.
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CROSSREFS
| Cf. A000578, A048785, A000290, A005117.
Sequence in context: A001223 A171991 A118776 * A147848 A193432 A129089
Adjacent sequences: A092517 A092518 A092519 * A092521 A092522 A092523
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KEYWORD
| nonn
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 06 2004
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