id:A056550 - OEIS Search Results

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Numbers n such that Sum_{k=1..n} sigma(k) is divisible by n, where sigma(k) = sum of divisors of k (A000203).

+0
2

1, 2, 8, 11, 17, 63, 180, 259, 818, 2161, 4441, 8305, 11998, 694218, 3447076, 4393603, 57402883, 73459800 (list; graph; listen)

	OFFSET	`1,2`
	FORMULA	`Values of n for which A024916(n)/n is integer.`
	MAPLE	`f := []: for i from 1 to 9000 do if add(sigma(n), n=1..i) mod i = 0 then f := [op(f), i] fi; od; f;`
	CROSSREFS	`Cf. A000203, A024916.` `Sequence in context: A045086 A064105 A129516 this_sequence A074263 A009420 A090746` `Adjacent sequences: A056547 A056548 A056549 this_sequence A056551 A056552 A056553`
	KEYWORD	`nonn`
	AUTHOR	`Asher Auel (asher.auel(AT)reed.edu) Jun 06 2000`
	EXTENSIONS	`More terms from Jud McCranie (j.mccranie(AT)comcast.net), Jul 04 2000`

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Last modified September 5 01:44 EDT 2008. Contains 143476 sequences.