[seqfan] Re: Do 20 and 105 eventually reach a prime in these sequences?

Alonso Del Arte alonso.delarte at gmail.com
Wed Sep 14 16:58:07 CEST 2011


Well, there's a difference between self-censorship and taking the time to
think about it and discuss it.

Anyway, y'all might be happy to know that 196, which doesn't reach a
palindrome under reverse-and-add (that we know of), does reach a prime under
this process, in less than fifty steps.

But it appears that most 3-digit numbers reach a prime in more than ten
steps but fewer than twenty.

Al

On Wed, Sep 14, 2011 at 10:08 AM, Marc LeBrun <mlb at well.com> wrote:

> >="Charles Greathouse" <charles.greathouse at case.edu>
> > suggests a sequence 4, 9, 16, 18, 25, 36, 49, ... "Numbers n for which
> > the exponent of the largest prime factor of n is even.".  Worth
> > submitting?
> >
>
> Absolutely!  Please do!
>
> (I continue to be surprised by the frequency of these queries I'm hearing.
> I feel another lecture coming on about the peril posed by too much
> (self)censorship of submissions to the OEIS.)
>
>
>
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>
> Seqfan Mailing list - http://list.seqfan.eu/
>



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