[seqfan] Re: number theory question about A000593

Alonso Del Arte alonso.delarte at gmail.com
Sat Jun 18 22:28:59 CEST 2011


This is a very interesting question, but at the same time I feel like the
answer should be on the tip of my tongue. At this point, however, I would
like to just give a little clarification: I think you meant to say "is an
odd prime," because a(2) = 1 rather than 3.

There might be some interesting new sequences here, such as A593(n) - n.

Al
On Sat, Jun 18, 2011 at 11:37 AM, Peter Lawrence
<peterl95124 at sbcglobal.net>wrote:

>
> I was tinkering with A000593 "sum of odd divisors of N" and noticed that
> empirically
>
> A(n)  =  n+1    IFF    isprime(n)                      <--- conjecture ???
>
>
> (a bit of finagling results in only needing to check for odd squares, so a
> simple C program
> verifies this out to 10^12 pretty fast)
>
>
> So I am wondering if this is actually true, and if so is there is any N.T.
> proof.
>
>
>
> apologies in advance if this is too off-topic for this list,
> thanks,
> Peter Lawrence.
>
> ______________________________**_________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>



More information about the SeqFan mailing list