[seqfan] Re: Add to an integer its distinct factors and loop

[Joshua Zucker]

On Thu, Jun 4, 2009 at 5:33 AM, Eric Angelini <Eric.Angelini at kntv.be> wrote:
> "Add to an integer N its distinct factors and loop"
[snip]
> 12-->2*6--->20-->2*10-->32-->2*16-->50-->2*25-->77-->7*11-->95--->...


"Its distinct factors" - why 2*10 for 20, and not 4*5?  I don't
understand how to choose which factor pair.

Maybe you mean "for N composite, let p be the smallest prime factor of
N, and add N + p + N/p" or something along those lines?

Does the "distinct" mean that I should say "for N composite and not
the square of a prime, ..."?

--Joshua Zucker