mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > XYYXF Project

Reply
 
Thread Tools
Old 2022-05-22, 09:27   #507
NorbSchneider
 
NorbSchneider's Avatar
 
"Norbert"
Jul 2014
Budapest

11101102 Posts
Default

Another new PRP:
37535^37674+37674^37535, 172338 digits.
NorbSchneider is offline   Reply With Quote
Old 2022-05-27, 05:47   #508
lghu
 
Nov 2019

3·5 Posts
Default

My 'Leyland-1M' project found this PRP:

211185^54364+54364^211185 is Fermat and Lucas PRP!

1000027 digits, index: 21589915517 (if my program is correct).
lghu is offline   Reply With Quote
Old 2022-05-27, 10:41   #509
pxp
 
pxp's Avatar
 
Sep 2010
Weston, Ontario

233 Posts
Default

Quote:
Originally Posted by lghu View Post
My 'Leyland-1M' project found this PRP:
211185^54364+54364^211185 is Fermat and Lucas PRP!
1000027 digits, index: 21589915517 (if my program is correct).
Well done! The Leyland-number index is correct. I have a dictionary of Leyland (x,y) pairs from (999999,10) to (1000999,10), sorted by magnitude and preceded by its Leyland-number index (21588818851 to 21628375832), so I can just look it up.
pxp is online now   Reply With Quote
Old 2022-05-31, 18:06   #510
pxp
 
pxp's Avatar
 
Sep 2010
Weston, Ontario

233 Posts
Default

Quote:
Originally Posted by pxp View Post
The date in my list is not from the FactorDB list but (primarily) the date used in PRPtop which is month/year. This is because I endeavoured to date all Leyland primes > 10000 digits, not just the ones that made it to FactorDB (quite a few did not). Even so, I had issues because not everyone submitted their primes to PRPtop. Where I could, I added missing primes to PRPtop on the person's behalf, but in these cases the PRPtop date would be somewhat later than the actual discovery date (which I gleaned from the mersenneforum thread) so I used the actual discovery dates. For a smallish number of primes I had no discovery date, so I used an estimate based on other similar-sized numbers contributed to PRPtop by the author. For my own contributions where I actually had a precise day of discovery, a couple of last-day-of-the-month finds show up in PRPtop dated the following month because I didn't submit them before midnight (PRPtop time). In those cases I used PRPtop months: close enough! In only one instance — Anatoly Selevich's L(8656,2929) — did I not have sufficient evidence of a probable discovery date. It may have been removed from PRPtop after it was proven prime (I resubmitted it in 2015). I went through Anatoly's submissions to PRPtop and finally settled on November 2007 as the most likely date of that find, although the evidence is far from certain. That is why in my Leyland primes indexing list, the date for L(8656,2929) is the only one preceded by a "~".
715 38951950 30008 (8656,2929) Anatoly Selevich ~Nov 2007 P

I have just now changed this line to:

715 38951950 30008 (8656,2929) Anatoly Selevich Dec 2007 P

I don't know why I hadn't thought of this before. The Internet Archive Wayback Machine has a Jan 2008 snapshot that definitively dates the PRP discovery.
pxp is online now   Reply With Quote
Old 2022-06-19, 18:30   #511
NorbSchneider
 
NorbSchneider's Avatar
 
"Norbert"
Jul 2014
Budapest

11810 Posts
Default

Another new PRP:
33^129128+129128^33, 196083 digits.
NorbSchneider is offline   Reply With Quote
Old 2022-06-24, 15:36   #512
NorbSchneider
 
NorbSchneider's Avatar
 
"Norbert"
Jul 2014
Budapest

2·59 Posts
Default

Another new PRP:
37803^37916+37916^37803, 173562 digits.
NorbSchneider is offline   Reply With Quote
Old 2022-06-26, 17:22   #513
storm5510
Random Account
 
storm5510's Avatar
 
Aug 2009
Not U. + S.A.

23×3×97 Posts
Default

Quote:
Originally Posted by NorbSchneider View Post
Another new PRP:
37803^37916+37916^37803, 173562 digits.
37803 ^ 37916 + 37916 ^ 37803 = ?
storm5510 is offline   Reply With Quote
Old 2022-06-26, 17:31   #514
paulunderwood
 
paulunderwood's Avatar
 
Sep 2002
Database er0rr

4,283 Posts
Default

Quote:
Originally Posted by storm5510 View Post
37803 ^ 37916 + 37916 ^ 37803 = ?
http://factordb.com/index.php?showid...00003609777732
paulunderwood is offline   Reply With Quote
Old 2022-06-28, 13:40   #515
storm5510
Random Account
 
storm5510's Avatar
 
Aug 2009
Not U. + S.A.

23×3×97 Posts
Default

Quote:
Originally Posted by paulunderwood View Post
Sorry, I asked the wrong question.

What are these calculation being done with?
storm5510 is offline   Reply With Quote
Old 2022-06-28, 13:56   #516
paulunderwood
 
paulunderwood's Avatar
 
Sep 2002
Database er0rr

4,283 Posts
Default

Quote:
Originally Posted by storm5510 View Post
Sorry, I asked the wrong question.

What are these calculation being done with?
mtsieve + OpenPFGW is my guess
paulunderwood is offline   Reply With Quote
Old 2022-06-28, 14:27   #517
rogue
 
rogue's Avatar
 
"Mark"
Apr 2003
Between here and the

24·421 Posts
Default

He has a special build of xyyxsieve because the way he is testing ranges is based upon decimal length of the candidates. The "out of the box" xyyxsieve is more efficient with a relatively square workspace, i.e. the range of x and y are similar in size. At one time I was working on changing xyyxsieve to be provide the "best of both worlds", but I couldn't get it to work and gave up. I might return to it someday.

The biggest challenge with xyyxsieve is that it is most efficient to sieve a very large search space once than to break that up into smaller chunks. But with a very large search space one needs a lot of memory.
rogue is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mersenne Primes p which are in a set of twin primes is finite? carpetpool Miscellaneous Math 4 2022-07-14 02:29
Leyland Primes: ECPP proofs Batalov XYYXF Project 57 2022-06-30 17:24
Distribution of Mersenne primes before and after couples of primes found emily Math 34 2017-07-16 18:44
On Leyland Primes davar55 Puzzles 9 2016-03-15 20:55
possible primes (real primes & poss.prime products) troels munkner Miscellaneous Math 4 2006-06-02 08:35

All times are UTC. The time now is 20:27.


Thu Sep 29 20:27:12 UTC 2022 up 42 days, 17:55, 0 users, load averages: 1.81, 1.34, 1.31

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, 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