id:A097703 - OEIS Search Results

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Numbers n such that m = 216n + 108 satisfies sigma(m) <> 2*usigma(m).

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	OFFSET	`1,2`
	COMMENT	`Conjecture: all numbers of form 3k + 1 are here. Other terms are listed in A097704.`
	MATHEMATICA	`usigma[n_] := Block[{d = Divisors[n]}, Plus @@ Select[d, GCD[ #, n/# ] == 1 &]]; Complement[ Range[157], (Select[ Range[37000], DivisorSigma[1, # ] == 2usigma[ # ] &] - 108)/216] (from Robert G. Wilson v Aug 28 2004)`
	CROSSREFS	`Complement of A097702. Cf. A063880.` `Sequence in context: A025357 A144020 A047845 this_sequence A104036 A050173 A078633` `Adjacent sequences: A097700 A097701 A097702 this_sequence A097704 A097705 A097706`
	KEYWORD	`nonn`
	AUTHOR	`Ralf Stephan (ralf(AT)ark.in-berlin.de), Aug 26 2004`

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Last modified December 6 19:58 EST 2009. Contains 170429 sequences.

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