[seqfan] Re: Factor Database

Charles Greathouse charles.greathouse at case.edu
Thu Sep 16 19:59:39 CEST 2010


There is a (long) discussion at the Mersenne forum on this topic, for
those interested:
http://mersenneforum.org/showthread.php?t=11119

This is probably the best way to contact the developer/maintainer, Syd.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Thu, Sep 16, 2010 at 11:56 AM, Alonso Del Arte
<alonso.delarte at gmail.com> wrote:
> That looks like a very useful website, though very thin on explanations. I
> tried it out with 210*z+199, which is admittedly not much of a test of its
> abilities.
>
> Al
>
> On Thu, Sep 16, 2010 at 11:25 AM, Hans Havermann <pxp at rogers.com> wrote:
>
>> I hadn't heard about this prior to Warut Roonguthai mentioning it this
>> morning on MathFun in reference to the Triangular + Triangular =
>> Factorial thread. For example, the factorizations of 4*z!+1 are:
>>
>> http://factordb.com/index.php?query=4*z%21%2B1&perpage=200
>>
>> Or, another example, the repunits:
>>
>> http://factordb.com/index.php?query=%2810%5Ez-1%29%2F9&perpage=200
>>
>> When I generated the latter earlier, one of the factors for R186 was
>> still shown as composite. I submitted the multiplication in the
>> "report factors" at the top and upon refreshing the Repunits, the
>> composite for R186 was gone! So we're talking real-time sharing here.
>>
>> A final example. I had spent 11 months last year re-calculating
>> Richard Guy's 776-term aliquot sequence for the number 46758. If
>> you're willing to wait 20 seconds:
>>
>>
>> http://factordb.com/sequences.php?se=1&eff=4&aq=46758&action=all&fr=0&to=100
>>
>> And you can show the graph with one click. I'm in heaven! ;)
>>
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>




More information about the SeqFan mailing list