A116895 - OEIS

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A116895

Least prime factor of n^n-1.

3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 13, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2 (list; graph; refs; listen; history; internal format)

	OFFSET	`2,1`
	COMMENTS	`If n is odd then a(n)=2; also, if n is even and not divisible by 3 then a(n)=3. - Zak Seidov, Mar 03 2006`
	EXAMPLE	`6^6-1=5731*43, so a(6)=5.`
	MATHEMATICA	`Table[FactorInteger[GCD[n^n-1, 200! ]][[1, 1]], {n, 2, 130}]`
	CROSSREFS	`Cf. A006486, A007571, A048861.` `Sequence in context: A093489 A066919 A084117 * A134267 A165258 A092962` `Adjacent sequences: A116892 A116893 A116894 * A116896 A116897 A116898`
	KEYWORD	`nonn`
	AUTHOR	`Giovanni Resta (g.resta(AT)iit.cnr.it), Mar 02 2006`

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Last modified February 14 14:07 EST 2012. Contains 205623 sequences.