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Warp wrote:
> Finding this information is surprisingly difficult, even in the modern
Sounds like a good test for Wolfram's Alpha. :-)
--
Darren New, San Diego CA, USA (PST)
There's no CD like OCD, there's no CD I knoooow!
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On Sun, 17 May 2009 10:40:05 -0400, Warp wrote:
> However, I can't find the
> answer to my question above.
I would guess that that piece of information changes quite frequently.
Factoring takes time, yes, but there's more than one number being
factored at any given time...
Jim
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> What is the smallest number for which it's unknown whether it's prime
> or composite?
>
>
In my (naive and not very documented) opinion, it should not be so much
more that the highest prime known (which seems to be 2^(43.112.609) -1,
if I believe Wolfram) : add 2, or 4, etc. and check if you can obtain
some trivial factor (like divisibility by 3) - if not then it's probably
unknown.
At second though, maybe your point is precisely that this smallest
number with unknown status can be much *smaller* than the highest prime
known ?
tuabiht
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Jim Henderson <nos### [at] nospam com> wrote:
> I would guess that that piece of information changes quite frequently.
It takes but a few seconds for a website to update for the latest data.
It's not like the internet were a printed encyclopedia.
> Factoring takes time, yes, but there's more than one number being
> factored at any given time...
A number begin factored doesn't mean its status is known.
--
- Warp
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Thibaut Jonckheere <tua### [at] mapsonyahoo fr> wrote:
> In my (naive and not very documented) opinion, it should not be so much
> more that the highest prime known (which seems to be 2^(43.112.609) -1,
Not all primes between the largest known prime and 2 are known. I'm
interested in what is the smallest number for which it hasn't been verified
if it's a prime or not.
> At second though, maybe your point is precisely that this smallest
> number with unknown status can be much *smaller* than the highest prime
> known ?
A lot smaller.
--
- Warp
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On Sun, 17 May 2009 14:28:56 -0400, Warp wrote:
> Jim Henderson <nos### [at] nospam com> wrote:
>> I would guess that that piece of information changes quite frequently.
>
> It takes but a few seconds for a website to update for the latest
> data.
> It's not like the internet were a printed encyclopedia.
From which source? If there are multiple people working on the project,
some aware of the work others are doing, and some not, you assume that
everyone working on it keeps everyone updated constantly as to their
progress.
>> Factoring takes time, yes, but there's more than one number being
>> factored at any given time...
>
> A number begin factored doesn't mean its status is known.
Exactly. See my above comment.
Jim
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Jim Henderson <nos### [at] nospam com> wrote:
> On Sun, 17 May 2009 14:28:56 -0400, Warp wrote:
> > Jim Henderson <nos### [at] nospam com> wrote:
> >> I would guess that that piece of information changes quite frequently.
> >
> > It takes but a few seconds for a website to update for the latest
> > data.
> > It's not like the internet were a printed encyclopedia.
> From which source? If there are multiple people working on the project,
> some aware of the work others are doing, and some not, you assume that
> everyone working on it keeps everyone updated constantly as to their
> progress.
> >> Factoring takes time, yes, but there's more than one number being
> >> factored at any given time...
> >
> > A number begin factored doesn't mean its status is known.
> Exactly. See my above comment.
Sorry, I didn't understand. "Exactly"? What exactly?
--
- Warp
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On Sun, 17 May 2009 16:47:33 -0400, Warp wrote:
> Jim Henderson <nos### [at] nospam com> wrote:
>> On Sun, 17 May 2009 14:28:56 -0400, Warp wrote:
>
>> > Jim Henderson <nos### [at] nospam com> wrote:
>> >> I would guess that that piece of information changes quite
>> >> frequently.
>> >
>> > It takes but a few seconds for a website to update for the latest
>> > data.
>> > It's not like the internet were a printed encyclopedia.
>
>> From which source? If there are multiple people working on the
>> project, some aware of the work others are doing, and some not, you
>> assume that everyone working on it keeps everyone updated constantly as
>> to their progress.
>
>> >> Factoring takes time, yes, but there's more than one number being
>> >> factored at any given time...
>> >
>> > A number begin factored doesn't mean its status is known.
>
>> Exactly. See my above comment.
>
> Sorry, I didn't understand. "Exactly"? What exactly?
Its status may not be known, but for any individual number that may be
being worked on, its status may not be known. It seems there is no
central place for people to say "I'm working on
1234567890123435674575623412341413412342323" or "I've just completed
128347938729759258761923419846957582091841035735235 and it is/is not
prime".
Jim
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> What is the smallest number for which it's unknown whether it's prime
> or composite?
1000000000000000000000000000000000
Oh, wait, you just worked out that is composite in your head, so ermm I
guess it's
1000000000000000000000000000000001
now :-)
BTW, how does everyone else know if such numbers have been tested or not,
it's not like prime numbers where they are published and announced, people
probably have done this without publishing the results, so it's just going
to be some relatively small number that just happens to have never been
tested by anyone. Good luck finding out what it is :-)
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"scott" <sco### [at] laptop com> wrote in message news:4a115772@news.povray.org...
> > What is the smallest number for which it's unknown whether it's prime
> > or composite?
>
> 1000000000000000000000000000000000
>
> Oh, wait, you just worked out that is composite in your head, so ermm I
> guess it's
>
> 1000000000000000000000000000000001
>
> now :-)
7 x 11^2 x 13 x 23 x 4093 x 8779 x 599144041 x 183411838171
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