Dan's Triangular numbers / Primes post

[Creighton Dement]

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> Date: Wed, 19 Oct 2005 05:31:09 +0200
> Subject: Re: Dan's Triangular numbers / Primes post
> From: Thomas Baruchel <baruchel at bluebottle.com>
> To: seqfan at ext.jussieu.fr

> On Mer, oct 19, 2005 at 12:09:41 +0200, Creighton Dement wrote:
> > I would like to post a link to a thread started by someone else on
> > sci.math that I find interesting. Perhaps some of the experts from
> > the seqfan list can be helpful to the seemingly very polite "Dan".
> > 
> > http://mathforum.org/kb/thread.jspa?threadID=1267639&tstart=0 
> 
> I don't understa
nd very well what your problem is. Is it a
> mathematical issue ? On the other hand, it may be rather technical if
> you don't know how to do (but it looks like you already posted on
> sci.math in the past).
> 
> If what you want is to answer to "Dan", why don't you do it ? If you
> want to "post a link" (probably an URL), why don't you copy this URL
> in a follow-up on sci.math ?
> 
> Below are the headers of Dan's message. Since I don't think I have the
> right to publish his full mail address (because of the SPAM), I
> replaced the three letters 'ack' with '...' in the From: header. You
> may use it if you want to post directly to him.
> 
> You can also use the 'Message-ID' to search for the message with a
> tool that would allow to you to answer him.
> 
> I hope I am a little helpful but your message isn't very clear about
> what you want to do.
> 
> Regards,
>
> Thomas Baruchel
> Home Page: http://baruchel.free.fr/~thomas/

Thank you for your reply. Sorry, for the confusion / for not being clear
enough. I would have thought this statement sufficed:
 
>Perhaps some of the experts from the seqfan list can be helpful to the
>seemingly very polite "Dan".

In other words, I do not consider myself expert enough on that topic to
be much help to him - who believes he has come up with something new
concerning the statement "an odd number greater than 3 is prime if it
can be written as the difference of two triangular numbers in exactly
two ways". If I thought I could have informed him whether his statement
were new, I highly doubt I would have posted to the seqfan list
(moreover, valid questions on sci.math often dissappear forever the next
day- unless they are totally off topic in which case they may stay on
the front page for several days).  You are definitely correct by hinting
that I already know how to post a message on sci.math!  
 
Though his conjecture is (first correctly formulated and then) proved by
two other posters, one of these writes:  "It is an intriguing pattern,
so worth being uncovered (nice going), and also worth being explained
[snip]"

So, is his statement really new? I was unaware of it in the first place
(within my vast areas of ignorance).  I am aware of the well-known
 
Theorem (Cauchy).  Every non-negative integer can be written as the sum
of k k-gon numbers ).  

It would therefore be easy to construct follow up questions:  Say, if an
odd number greater than 3 is prime if it can be written as the
difference of two triangular numbers in exactly two ways- then what
about the other k-gonal numbers? 

That, however, was not the reason for my post to the list. 
Regarding your last question
> If you want to "post a link" (probably an URL), why don't you copy
this URL
> in a follow-up on sci.math ?

Not sure what you mean here. Perhaps you can reformulate the question
and send it directly to me? 
 
Thanks, 
Creighton