Factoring database

[bur]

Originally Posted by Mini-Geek

"Silvester/Euclid sequence"s should not when a prime term is reached (by the definitions at Wikipedia), but they do. E.g. http://factordb.com/sequences.php?se...20&fr=0&to=100

This is still the case, it's blocking the "real" Silvester sequence (a(0) = 2) which just stops at 2. Since factorization is not required to continue the sequence it should just proceed.

[MisterBitcoin]

I started a worker on C86s. Most are done within a few secs.

Any one else working on small composites?

[richs]

I have had one worker on C81+ for the past few months. I was staying afloat until some spammer overflowed the C70's+.

[chris2be8]

I'm working on C70-C80s. And occasionally looking for easy numbers in the 80-90 digits range (easy usually means doable with SNFS).

I noticed a lot of numbers like 50##/206 (product of first 50 primes divided by some small number) and set a script going to factor them. That cleared out about 12,000 of them (mainly limited by how many updates per hour factordb would allow).

If you can think of a sensible reason for adding them to factordb in the first place I'd be interested to hear it.

Chris

[MisterBitcoin]

Originally Posted by chris2be8

I'm working on C70-C80s. And occasionally looking for easy numbers in the 80-90 digits range (easy usually means doable with SNFS).

I noticed a lot of numbers like 50##/206 (product of first 50 primes divided by some small number) and set a script going to factor them. That cleared out about 12,000 of them (mainly limited by how many updates per hour factordb would allow).

If you can think of a sensible reason for adding them to factordb in the first place I'd be interested to hear it.

Chris

After about 22 hours in C86:

============================================================
Runtime (H:M:S).....................: 0022:34:45
Time waiting for composites (H:M)...: 0000:00
Composite range.....................: 86 - 86 digits

Report factors for composite #......: 3716
Factored C86 in.....................: 2.3 sec.

        New factors added...........: 2 / 4825
        Factors already known.......: 1 / 1832
        Small factors...............: 0 / 11190

        Only small factors..........: 240
        Worker collisions...........: 6

        Total page requests.........: 7432
============================================================
  164.6 composites/hr
  329.1 page requests/hr
  418.5 page requests/hr (last 60 composite requests)
  306.9 new factors added/hr (last 60 composite requests)

[MattcAnderson]

I really enjoy factordb.com
It is very impressive and can handle 200 digit numbers.

my latest contribution is

66640677780239073397348544449935115508844251925178751602054631202961

<68 digits>
is

3138306167<10> · 2123460052...83<59>

So C68 = P10 * P59.
Used Maple computer algebra system ifactor() command.

Very interesting. Good mathematical trivia.

[Uncwilly]

Originally Posted by MattcAnderson

I really enjoy factordb.com
It is very impressive and can handle 200 digit numbers.

my latest contribution is

66640677780239073397348544449935115508844251925178751602054631202961

<68 digits>
is

3138306167<10> · 2123460052...83<59>

So C68 = P10 * P59.

That is trivial and a waste of factordb

[MattcAnderson]

Hi again all,
Factordb.com has a limit to largest input it would take.
I received the error.
Error: Limit of about 10.000.000 digits exceeded

I found an interesting result for a C1,000,000

[10^1,000,000] + 1

so that is (1- to the power of one million) + 1

factordb comes back with 12 prime factors and 2 composite factors.

Woo Hoo

Matt

[Happy5214]

Originally Posted by MattcAnderson

Hi again all,
Factordb.com has a limit to largest input it would take.
I received the error.
Error: Limit of about 10.000.000 digits exceeded

I found an interesting result for a C1,000,000

[10^1,000,000] + 1

so that is (1- to the power of one million) + 1

factordb comes back with 12 prime factors and 2 composite factors.

Woo Hoo

Matt

Check the date (found under "More information"):

Create time
Before November 4, 2018, 12:20 am

There was a major database reset around that time that reset all of the dates, so this entry is older, probably much, much older.

[chris2be8]

@ MattcAnderson

If you want to do something useful try running the script in https://mersenneforum.org/showthread...=16849&page=43 post 471 for a few days. There are a lot of smallish composites in factordb and it could do with some help factoring them.

Chris

[Dr Sardonicus]

Originally Posted by chris2be8

@ MattcAnderson

If you want to do something useful try running the script in https://mersenneforum.org/showthread...=16849&page=43 post 471 for a few days. There are a lot of smallish composites in factordb and it could do with some help factoring them.

Chris

Alas, this post indicates he might be part of the problem...