A048106 - OEIS

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A048106

Number of unitary divisors of n (A034444) - number of non-unitary divisors of n (A048105).

1, 2, 2, 1, 2, 4, 2, 0, 1, 4, 2, 2, 2, 4, 4, -1, 2, 2, 2, 2, 4, 4, 2, 0, 1, 4, 0, 2, 2, 8, 2, -2, 4, 4, 4, -1, 2, 4, 4, 0, 2, 8, 2, 2, 2, 4, 2, -2, 1, 2, 4, 2, 2, 0, 4, 0, 4, 4, 2, 4, 2, 4, 2, -3, 4, 8, 2, 2, 4, 8, 2, -4, 2, 4, 2, 2, 4, 8, 2, -2, -1, 4, 2, 4, 4, 4, 4, 0, 2, 4, 4, 2, 4, 4, 4, -4, 2, 2, 2 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	FORMULA	`a[ n ]=2^(1+r(n)) - d(n) =2^(1+A001221(n))-A000005(n).` `a(n) = -Sum_{ d divides n } (-1)^mu(d). - Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 24 2002`
	CROSSREFS	`Cf. A008683.` `Sequence in context: A125912 A127677 A007427 * A156260 A056671 A055076` `Adjacent sequences: A048103 A048104 A048105 * A048107 A048108 A048109`
	KEYWORD	`sign`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu)`

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Last modified February 15 18:11 EST 2012. Contains 205835 sequences.