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A072747 Counting factor 2 in squarefree numbers <=n. 4
0, 1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 11, 11, 11, 12, 12, 12, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 17, 17, 18, 18, 18, 19, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 25, 25, 26, 26, 26 (list; graph; refs; listen; history; internal format)
OFFSET

1,5

EXAMPLE

The first 10 squarefree numbers are: 1, 2, 3, 5, 6=2*3, 7, 10=2*5, 11, 13 and 14=2*7

2, 6, 10 and 14 are divisible by 2, therefore a(10)=4.

CROSSREFS

Cf. A005117, A072748, A072749, A072750, A072751.

Sequence in context: A143824 A034463 A071996 * A194295 A194287 A194303

Adjacent sequences:  A072744 A072745 A072746 * A072748 A072749 A072750

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 08 2002

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Last modified February 15 23:53 EST 2012. Contains 205860 sequences.