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A072748
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Counting factor 3 in squarefree numbers <=n.
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4
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0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 9, 9, 9, 10, 10, 10, 10, 10, 10, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 15, 15, 15, 15, 15, 16, 16, 17, 17, 17, 17, 17, 18, 18, 19, 19, 19, 19, 19, 20, 20, 21, 21
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,5
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EXAMPLE
| The first 10 squarefree numbers are: 1, 2, 3, 5, 6=2*3, 7, 10=2*5, 11, 13 and 14=2*7
3 and 6 are divisible by 3, therefore a(10)=2.
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CROSSREFS
| Cf. A005117, A072747, A072749, A072750, A072751.
Sequence in context: A131996 A090618 A186444 * A174631 A030603 A092670
Adjacent sequences: A072745 A072746 A072747 * A072749 A072750 A072751
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KEYWORD
| nonn
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 08 2002
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