id:A054785 - OEIS Search Results

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Sigma[2n]-Sigma[n], where Sigma is the sum of divisors of n, A000203.

+0
3

2, 4, 8, 8, 12, 16, 16, 16, 26, 24, 24, 32, 28, 32, 48, 32, 36, 52, 40, 48, 64, 48, 48, 64, 62, 56, 80, 64, 60, 96, 64, 64, 96, 72, 96, 104, 76, 80, 112, 96, 84, 128, 88, 96, 156, 96, 96, 128, 114, 124, 144, 112, 108, 160, 144, 128, 160, 120, 120, 192, 124, 128, 208 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`n=9: sigma(2n)=18+9+6+3+2+1=39, sigma(n)=9+3+1=13, a(n)=39-13=26.`
	FORMULA	`a(n)=A000203(2n)-A000203(n)` `a(2n) = A000203(n) + A000593(2n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 23 2008`
	CROSSREFS	`Cf. A000203.` `Equals 2 * A002131.` `Sequence in context: A129280 A103224 A078750 this_sequence A123263 A008218 A073043` `Adjacent sequences: A054782 A054783 A054784 this_sequence A054786 A054787 A054788`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), May 22 2000`

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.

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