id:A053807 - OEIS Search Results

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Sum_{k=1..n, n mod k = 1} k^2.

+0
2

0, 0, 4, 9, 20, 25, 49, 49, 84, 90, 129, 121, 209, 169, 249, 259, 340, 289, 454, 361, 545, 499, 609, 529, 849, 650, 849, 819, 1049, 841, 1299, 961, 1364, 1219, 1449, 1299, 1910, 1369, 1809, 1699, 2209, 1681, 2499, 1849, 2561, 2365, 2649 (list; graph; listen)

	OFFSET	`1,3`
	FORMULA	`a(n) = sigma_2(n-1) - 1.`
	CROSSREFS	`Cf. A001157.` `Sequence in context: A136769 A115075 A063454 this_sequence A066109 A030734 A073360` `Adjacent sequences: A053804 A053805 A053806 this_sequence A053808 A053809 A053810`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Apr 07 2000`

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.

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