id:A070549 - OEIS Search Results

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a(n)=Card(k 0<k<=n such that mu(k)=-1).

+0
2

0, 1, 2, 2, 3, 3, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 14, 15, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 20, 21, 22, 22, 22, 23, 24, 24, 25, 25, 25, 25, 25, 26 (list; graph; listen)

	OFFSET	`1,3`
	COMMENT	`mu(k)=-1 if k is the product of an odd number of distinct primes. See A057627 for mu(k)=0.`
	PROGRAM	`(PARI) for(n=1, 150, print1(sum(i=1, n, if(moebius(i)+1, 0, 1)), ", "))`
	CROSSREFS	`Sequence in context: A071868 A082447 A000720 this_sequence A074796 A139789 A061070` `Adjacent sequences: A070546 A070547 A070548 this_sequence A070550 A070551 A070552`
	KEYWORD	`easy,nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), May 02 2002`

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Last modified July 26 13:41 EDT 2008. Contains 142293 sequences.

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