v5 PrimeNet factor validation - test it now!
 

Can anyone break this v5 factor validation test for any exponent n and factor f ? Post any n, f that you find breaks the test.

http: //v5.mersenne.org/v5server/gimps/mpftest.php ? n=<exponent> & f=<factor>

Examples:

[url]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=25196683&f=1745801539203503481761[/url]

1745801539203503481761 IS FACTOR of M(25196683)

[url]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=25196683&f=1745801539203503481763[/url]

1745801539203503481763 is NOT factor of M(25196683)

[url]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=2&f=klingon[/url]

klingon is NOT factor of M(2)

True, but not true. :D

[url]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=8&f=5[/url]

5 is NOT factor of M(8)

Found one
 

[url]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=23292847&f=8092687948661261082412157958831[/url]

8092687948661261082412157958831 is NOT factor of M(23292847)

23292847 F 103 8092687948661261082412157958831 14-Feb-04 01:24 PJM-Borg01

EDIT: Scott saw this already.

Maybe pull a dump from v4 for all factors found and script them all through the new code?

[URL="http://v5.mersenne.org/v5server/gimps/mpftest.php?n=127&f=1"]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=127&f=1[/URL]

1 is NOT factor of M(127)


[URL="http://v5.mersenne.org/v5server/gimps/mpftest.php?n=128&f=3"]http://v5.mersenne.org/v5server/gimps/mpftest.php?n=128&f=3[/URL]
3 is NOT factor of M(128)
However:
M(128)=340282366920938463463374607431768211455 = 3 x 5 x 17 x 257 x 641 x 65537 x 274177 x 6700417 x 67280421310721

Hmm, the notes in the code I'm using cites these restrictions:
[INDENT](a) 79999999 >= odd exponent >= 727
(b) factor > 9, no leading zeros[/INDENT]
so let's stay within those.

For Paulie's 8092687948661261082412157958831 of M(23292847), I'm wondering if that's an invalid factor report. The GNU Multiple Precision Arithmetic Library (GMP) try it site [url]http://www.swox.com/gmp/#TRY[/url] when given:
[INDENT](2^23292847-1) mod 8092687948661261082412157958831[/INDENT]
Responds:
[INDENT]The result of executing (2^23292847-1) mod 8092687948661261082412157958831 is:
computation took 0 ms
output conversion took 0 ms
715926209409172266387763954144
[/INDENT]
instead of the expected 0 result.

As a check:
[INDENT]The result of executing (2^25196683-1) mod 1745801539203503481761 is:
computation took 0 ms
output conversion took 0 ms
0[/INDENT]
as expected.

[QUOTE=Old man PrimeNet]Hmm, the notes in the code I'm using cites these restrictions:
[INDENT](a) 79999999 >= odd exponent >= 727
(b) factor > 9, no leading zeros[/INDENT]
so let's stay within those.[/QUOTE]You may be please to know that when I tested 2^1023-1 as a factor of M1023 it passed.

Nobody else seems to have tested that Mn is a factor of Mn

Paul

If that's the case, I want to LL test that canidate! I sent a note to George.

You really ought to parse out non-digits from those arguments. Otherwise, one can put [url=http://v5.mersenne.org/v5server/gimps/mpftest.php?n=127&f=%3Cimg%20src=http://www.mersenneforum.org/avatars/avatar595_0.gif%3E]anything they want[/url] in there!:whistle:

I don't know the exact codes, but someone could probably compromise your server this way.

4440772988630248159 IS FACTOR of M(62069197)

Just found that, so, works for me.

According to the Factors file, the factor of 23292847 is actually:

18092687948661261082412157958831, which passes the test OK.

For those of you who don't like typing in URLs, [url=http://geocities.com/dchia1010/factor-test.html]here[/url] is an web-based version using forms.

Here is my HTML source code:

[code]<title>Mersenne factor verification tool for PrimeNet</title>

<center><br><font size=4>Mersenne factor verification tool for PrimeNet</font>


<form action=http://v5.mersenne.org/v5server/gimps/mpftest.php method=get>

<table width=245 cellspacing=0 border=1 bordercolor=black cellpadding=4>

<tr><td width=70><center><b>Exponent:</b></center></td><td><center><input name=n></center></td></tr>
<tr><td width=70><center><b>Factor:</b></center></td><td><center><input name=f></center></td></tr></table>
<br>
<input value=check type=submit>

</form>

</center>

<center><b>Note:</b> The source code of this page is available as public domain.</center>[/code]