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A116895 Least prime factor of n^n-1. 0
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=5*7*31*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.