id:A115911 - OEIS Search Results

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Numbers n such that phi(n) times sigma(n) is a triangular number.

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1, 2, 9, 11, 23, 118, 373, 556, 1332, 2420, 3081, 5251, 7642, 12671, 116836, 127627, 135861, 172676, 198912, 365408, 421902, 426710, 901273, 921736, 954068, 1001396, 1003333, 1006567, 1077452, 1161754, 1162514, 1364225, 1632361 (list; graph; listen)

	OFFSET	`1,2`
	EXAMPLE	`phi(1003333)*sigma(1003333)=1003888529280=T(1416960).`
	CROSSREFS	`Cf. A069066.` `Sequence in context: A041581 A042463 A081613 this_sequence A065596 A042053 A134775` `Adjacent sequences: A115908 A115909 A115910 this_sequence A115912 A115913 A115914`
	KEYWORD	`nonn`
	AUTHOR	`Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 06 2006`

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.

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