id:A107912 - OEIS Search Results

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Numbers n that require two iterations of the sigma function to be >= 2n.

+0
4

2, 3, 4, 5, 7, 8, 10, 11, 14, 15, 16, 17, 19, 21, 22, 23, 26, 27, 29, 31, 32, 33, 34, 35, 38, 39, 41, 44, 45, 46, 47, 50, 51, 52, 53, 55, 57, 58, 59, 62, 63, 64, 65, 68, 69, 71, 74, 75, 76, 77, 79, 82, 83, 85, 86, 87, 89, 91, 92, 93, 94, 95, 98, 99, 101, 103, 105, 106, 107 (list; graph; listen)

	OFFSET	`0,1`
	REFERENCES	`Cf. A000203, A055021, A107913, A107914.`
	EXAMPLE	`Sigma(8)=15 but sigma(sigma(8))=25, so 8 is in the sequence.`
	CROSSREFS	`Sequence in context: A065003 A056177 A025199 this_sequence A066077 A103740 A034155` `Adjacent sequences: A107909 A107910 A107911 this_sequence A107913 A107914 A107915`
	KEYWORD	`nonn`
	AUTHOR	`Jud McCranie (j.mccranie(AT)comcast.net), May 27 2005`

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Last modified December 10 00:48 EST 2009. Contains 170565 sequences.

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