[seqfan] Re: Is this right? smallest prime factor of smaller of amicable pair

T. D. Noe noe at sspectra.com
Mon Aug 16 08:24:32 CEST 2010


At 11:14 PM -0700 8/15/10, Jonathan Post wrote:
>2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 3, 2, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2,
>2, 2, 2, 2, 2, 2, 3, 2, 2
>smallest prime factor of smaller of amicable pair
>a(n) = A020639(A002025(n)) =   Lpf(A002025(n)) = sigma(A002025(n))-A002025(n).
>Must always be 2 or 3?


It is true for all the terms in the b-file for A063990, which includes the
larger of the amicable pair also.

Tony





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