id:A072815 - OEIS Search Results

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Sum of proper divisors of 6n + 1.

+0
1

0, 1, 1, 1, 6, 1, 1, 1, 8, 17, 1, 1, 1, 1, 23, 21, 1, 1, 1, 29, 12, 1, 27, 1, 35, 1, 1, 1, 14, 48, 1, 29, 1, 1, 47, 1, 39, 1, 1, 53, 1, 33, 35, 45, 59, 1, 1, 1, 18, 65, 51, 1, 1, 41, 84, 1, 1, 57, 1, 77, 20, 1, 1, 1, 101, 41, 1, 45, 89, 1, 68 (list; graph; listen)

	OFFSET	`0,5`
	COMMENT	`the square root of t(n) < s(t(4n-1, 4n-2, 4n-3, 4n-4)) < s(t(4n)).`
	LINKS	`Eric Weisstein's World of Mathematics, Perfect Numbers`
	FORMULA	`s(t(n)), where t(n)=6n + 1 and s(n) is the restricted divisor function.`
	EXAMPLE	`a(1) = s(t(1))=1 since t(1)=7 and s(7)=1 under the definition of the restricted divisor function.`
	CROSSREFS	`Sequence in context: A064793 A034460 A063919 this_sequence A080304 A166142 A050449` `Adjacent sequences: A072812 A072813 A072814 this_sequence A072816 A072817 A072818`
	KEYWORD	`nonn`
	AUTHOR	`Hisanobu Shinya (ilikemathematics(AT)hotmail.com), Jul 14 2002`

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Last modified November 24 14:25 EST 2009. Contains 167438 sequences.

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