id:A057723 - OEIS Search Results

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Sum of positive divisors of n that are divisible by every prime that divides n.

+0
3

1, 2, 3, 6, 5, 6, 7, 14, 12, 10, 11, 18, 13, 14, 15, 30, 17, 24, 19, 30, 21, 22, 23, 42, 30, 26, 39, 42, 29, 30, 31, 62, 33, 34, 35, 72, 37, 38, 39, 70, 41, 42, 43, 66, 60, 46, 47, 90, 56, 60, 51, 78, 53, 78, 55, 98, 57, 58, 59, 90, 61, 62, 84, 126, 65, 66, 67, 102, 69, 70 (list; graph; listen)

	OFFSET	`1,2`
	FORMULA	`If n = Product p_i^e_i then a(n) = Product (p_i + p_i^2 + ... + p_i^e_i).`
	EXAMPLE	`The divisors of 12 that are divisible by both 2 and 3 are 6 and 12. So a(12) = 6 + 12 = 18.`
	CROSSREFS	`Cf. A000203, A049060, A060640.` `Sequence in context: A096861 A118738 A051377 this_sequence A142151 A003968 A076734` `Adjacent sequences: A057720 A057721 A057722 this_sequence A057724 A057725 A057726`
	KEYWORD	`nonn,mult`
	AUTHOR	`Leroy Quet (qq-quet(AT)mindspring.com), Oct 27 2000`

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Last modified November 21 14:49 EST 2008. Contains 150807 sequences.

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