id:A071090 - OEIS Search Results

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Sum of middle divisors of n.

+0
9

1, 1, 0, 2, 0, 5, 0, 2, 3, 0, 0, 7, 0, 0, 8, 4, 0, 3, 0, 9, 0, 0, 0, 10, 5, 0, 0, 11, 0, 11, 0, 4, 0, 0, 12, 6, 0, 0, 0, 13, 0, 13, 0, 0, 14, 0, 0, 14, 7, 5, 0, 0, 0, 15, 0, 15, 0, 0, 0, 16, 0, 0, 16, 8, 0, 17, 0, 0, 0, 17, 0, 23, 0, 0, 0, 0, 18, 0, 0, 18, 9, 0, 0, 19, 0, 0, 0, 19, 0, 19, 20, 0, 0 (list; graph; listen)

	OFFSET	`1,4`
	COMMENT	`Divisors are in the half-open interval [sqrt(n/2), sqrt(n*2)).`
	MATHEMATICA	`Table[Plus @@ Select[ Divisors[n], Sqrt[n/2] <= # < Sqrt[n*2] &], {n, 1, 95}]`
	CROSSREFS	`Cf. A067742.` `Adjacent sequences: A071087 A071088 A071089 this_sequence A071091 A071092 A071093` `Sequence in context: A069025 A066442 A086134 this_sequence A105221 A061376 A058974`
	KEYWORD	`nonn,easy`
	AUTHOR	`njas, May 27 2002`
	EXTENSIONS	`Extended by Robert G. Wilson v (rgwv(AT)rgwv.com), May 30 2002`

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Last modified October 11 09:12 EDT 2008. Contains 144832 sequences.

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