mersenneforum.org Found a factor? Post it here.
 User Name Remember Me? Password
 Register FAQ Search Today's Posts Mark Forums Read

 2011-01-07, 06:57 #45 ckdo     Dec 2007 Cleves, Germany 21216 Posts M39512171 has a factor: 23887910757239756825399 k = 2039*71597*2070643
 2011-01-10, 18:49 #46 ckdo     Dec 2007 Cleves, Germany 2·5·53 Posts M90012887 has a factor: 439952565941844992833877634700202506740401 k1 = 3*3*5*7*11*19*52177399 k2 = 5*11*71851282747
2011-01-10, 19:14   #47
KingKurly

Sep 2010
Annapolis, MD, USA

101111112 Posts

Quote:
 Originally Posted by ckdo M90012887 has a factor: 439952565941844992833877634700202506740401 k1 = 3*3*5*7*11*19*52177399 k2 = 5*11*71851282747
Goodness, that's a large factor. P-1, I presume?

2011-01-10, 19:53   #48
ckdo

Dec 2007
Cleves, Germany

2·5·53 Posts

Quote:
 Originally Posted by KingKurly Goodness, that's a large factor. P-1, I presume?
TF. First dual 70 bit factors I've seen for an exponent.

2011-01-12, 17:22   #49
lorgix

Sep 2010
Scandinavia

3·5·41 Posts

Quote:
 Originally Posted by ckdo TF. First dual 70 bit factors I've seen for an exponent.
I didn't know that was possible.

2011-01-12, 17:53   #50
TimSorbet
Account Deleted

"Tim Sorbera"
Aug 2006
San Antonio, TX USA

10B716 Posts

Quote:
 Originally Posted by lorgix I didn't know that was possible.
Why not? There's no reason a number can't have two factors that happen to have the same bit length. There's probably about a 1/4900 (70^(-2)) chance that any particular Mersenne number has two factors that are 70 bits long, so it should be rare, but it's possible.

2011-01-12, 18:27   #51
lorgix

Sep 2010
Scandinavia

10011001112 Posts

Quote:
 Originally Posted by Mini-Geek Why not? There's no reason a number can't have two factors that happen to have the same bit length. There's probably about a 1/4900 (70^(-2)) chance that any particular Mersenne number has two factors that are 70 bits long, so it should be rare, but it's possible.
I thought it would stop after finding the smaller one.

I wouldn't have been surprised to see a composite factor found by P-1.

2011-01-12, 18:43   #52
axn

Jun 2003

124748 Posts

Quote:
 Originally Posted by Mini-Geek Why not? There's no reason a number can't have two factors that happen to have the same bit length. There's probably about a 1/4900 (70^(-2)) chance that any particular Mersenne number has two factors that are 70 bits long, so it should be rare, but it's possible.
Because prime95 will stop at the first found factor?!

2011-01-12, 19:41   #53
ET_
Banned

"Luigi"
Aug 2002
Team Italia

10010111110012 Posts

Quote:
 Originally Posted by axn Because prime95 will stop at the first found factor?!
Not anymore, IIRC

Luigi

 2011-01-12, 19:59 #54 lorgix     Sep 2010 Scandinavia 3·5·41 Posts Why multiply them, instead of reporting them as they are found?
2011-01-12, 20:48   #55
axn

Jun 2003

22×32×151 Posts

Quote:
 Originally Posted by ET_ Not anymore, IIRC Luigi
Huh? It used to be that, once upon a time, p95 used to go ahead with TF even if a factor was found, just to make sure that no _smaller_ factor was missed. Then, that was removed. You mean to say that this (mis)feature has been reintroduced?!

 Similar Threads Thread Thread Starter Forum Replies Last Post Andrew Usher Lounge 18 2023-01-05 13:23 stanneraustin Homework Help 0 2022-10-04 15:17 Branger Factoring 15 2019-09-05 15:03 Axel Fox Lone Mersenne Hunters 19 2003-10-19 07:40 remaker Software 4 2002-10-17 08:18

All times are UTC. The time now is 07:07.

Sun Jan 29 07:07:49 UTC 2023 up 164 days, 4:36, 0 users, load averages: 0.52, 0.93, 0.98

Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.

≠ ± ∓ ÷ × · − √ ‰ ⊗ ⊕ ⊖ ⊘ ⊙ ≤ ≥ ≦ ≧ ≨ ≩ ≺ ≻ ≼ ≽ ⊏ ⊐ ⊑ ⊒ ² ³ °
∠ ∟ ° ≅ ~ ‖ ⟂ ⫛
≡ ≜ ≈ ∝ ∞ ≪ ≫ ⌊⌋ ⌈⌉ ∘ ∏ ∐ ∑ ∧ ∨ ∩ ∪ ⨀ ⊕ ⊗ 𝖕 𝖖 𝖗 ⊲ ⊳
∅ ∖ ∁ ↦ ↣ ∩ ∪ ⊆ ⊂ ⊄ ⊊ ⊇ ⊃ ⊅ ⊋ ⊖ ∈ ∉ ∋ ∌ ℕ ℤ ℚ ℝ ℂ ℵ ℶ ℷ ℸ 𝓟
¬ ∨ ∧ ⊕ → ← ⇒ ⇐ ⇔ ∀ ∃ ∄ ∴ ∵ ⊤ ⊥ ⊢ ⊨ ⫤ ⊣ … ⋯ ⋮ ⋰ ⋱
∫ ∬ ∭ ∮ ∯ ∰ ∇ ∆ δ ∂ ℱ ℒ ℓ
𝛢𝛼 𝛣𝛽 𝛤𝛾 𝛥𝛿 𝛦𝜀𝜖 𝛧𝜁 𝛨𝜂 𝛩𝜃𝜗 𝛪𝜄 𝛫𝜅 𝛬𝜆 𝛭𝜇 𝛮𝜈 𝛯𝜉 𝛰𝜊 𝛱𝜋 𝛲𝜌 𝛴𝜎𝜍 𝛵𝜏 𝛶𝜐 𝛷𝜙𝜑 𝛸𝜒 𝛹𝜓 𝛺𝜔