A129972 - OEIS

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A129972

a(n)=sum(k=1,n,(-1)^(k-1)*floor(n/k)*mu(k)).

1, 3, 3, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 7, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Consists of the n-th odd number (A005408(n) = 2n+1) repeated 2^(n-1) times (since a(n)=a(n-1) except when a(n)>a(n-1) which happens for n a power of 2). - Jonathan Vos Post (jvospost3(AT)gmail.com), Jun 17 2007`
	FORMULA	`a(n)=2*floor(log(n)/log(2))+1`
	PROG	`(PARI) a(n)=2*floor(log(n)/log(2))+1`
	CROSSREFS	`Cf. A005408.` `Sequence in context: A197100 A136027 A133772 * A130829 A196386 A035158` `Adjacent sequences: A129969 A129970 A129971 * A129973 A129974 A129975`
	KEYWORD	`nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 13 2007`

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Last modified February 14 19:37 EST 2012. Contains 205663 sequences.