A054021 - OEIS

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A054021

Numbers n such that Chowla's function of n is divisible by the number of proper divisors of n.

2, 3, 4, 5, 7, 8, 11, 12, 13, 14, 17, 18, 19, 23, 24, 26, 27, 29, 31, 32, 35, 37, 38, 40, 41, 43, 47, 52, 53, 56, 59, 61, 62, 63, 65, 66, 67, 71, 73, 74, 77, 79, 83, 86, 88, 89, 90, 92, 95, 97, 101, 103, 104, 107, 109, 110, 112, 113, 119, 122, 125, 127, 128, 131, 134, 136 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`Chowla's function (A048050) = sum of divisors of n except 1 and n.`
	MAPLE	`with(numtheory):` [seq(`if`((sigma(i)-i-1) mod (tau(i)-1)=0, i, print( )), i=2..1000)];
	CROSSREFS	`Complement is A054020 Cf. A032741, A048050, A054015.` `Sequence in context: A034296 A075745 A100289 * A066191 A166159 A169693` `Adjacent sequences: A054018 A054019 A054020 * A054022 A054023 A054024`
	KEYWORD	`nonn`
	AUTHOR	`Asher Auel (asher.auel(AT)reed.edu) Jan 19, 2000`

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Last modified February 15 15:18 EST 2012. Contains 205823 sequences.