id:A074816 - OEIS Search Results

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a(n) = sum(d|n, tau(d)*mu(d)^2 ).

+0
3

1, 3, 3, 3, 3, 9, 3, 3, 3, 9, 3, 9, 3, 9, 9, 3, 3, 9, 3, 9, 9, 9, 3, 9, 3, 9, 3, 9, 3, 27, 3, 3, 9, 9, 9, 9, 3, 9, 9, 9, 3, 27, 3, 9, 9, 9, 3, 9, 3, 9, 9, 9, 3, 9, 9, 9, 9, 9, 3, 27, 3, 9, 9, 3, 9, 27, 3, 9, 9, 27, 3, 9, 3, 9, 9, 9, 9, 27, 3, 9, 3, 9, 3, 27, 9, 9, 9, 9, 3, 27, 9, 9, 9, 9, 9, 9, 3, 9, 9, 9 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`Terms are powers of 3.`
	LINKS	`R. Zumkeller, Table = of n, a(n) for n = 1..10000`
	FORMULA	`a(n)=3^m if n is divisible by m distinct primes. i.e. a(n)=3 if n is in A000961; a(n)=9 if n is in A007774 ...` `a(n) = 3^A001221(n). Multiplicative with a(p^e)=3. - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 09 2002.`
	CROSSREFS	`Cf. A001221, A034444, A124508.` `Sequence in context: A098528 A078229 A007428 this_sequence A111575 A161836 A087576` `Adjacent sequences: A074813 A074814 A074815 this_sequence A074817 A074818 A074819`
	KEYWORD	`nonn,mult`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 08 2002`

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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.

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