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Wonderful news from Takahiro Nohara, who found the third Fermat factor of 2008!
"I found a new prime factor of the Fermat number today. (3rd May): 28949 . 2⁴⁸⁶²⁷+1 is a Factor of   F₄₈₆₂₄. I used FermFact.exe, LLR.exe and PFGW.exe to search this number. This is 3rd factor of Fermat number found by me and it has took close to five years since previuos report.".
Congratulations to Takahiro Nohara!
- Maximilian Pacher Strikes again! Maxi found the second Fermat factor of 2008!
"When I sent you my last Fermat-Factor of F1710. And you have written "a third factor could be near the corner". Now, one month later, I am of the opinion, that it is time to recover a new factor: 364182745 . 2¹⁷²⁴+1 is a Factor of   F₁₇₂₂!!!! I am very happy, that I have found this factor so shortly after my last one. This is my third Fermat-factor an the second in this year if I remember correctly. I used "NewPGen", "PRP" and "WinPFGW".
Congratulations again, Maximilian! Now we're waiting for the third!
- Maximilian Pacher found the first Fermat factor of 2008!
"After 7 years of searching, I'm very happy to announce my second Fermat factor: 351276975 . 2¹⁷¹⁹+1 divides   F₁₇₁₀! I have been searching for Fermat-factors since 2001 and this factor is my second one (my first one is 2018719057*2¹¹⁶²+1, that is a factor of F(1160)). I hope, it will not be the last one."
Maxi found this factor using "NewPGen", "PRP" and "WinPFGW" programs.
Congratulations, Maximilian!
- The site has been successfully transferred. Enjoy it!
- I am changing the domain maintainer, so expect some outages in the next days.
- Souichi Murata found a new factor:  485 . 2 ³³⁸²⁹⁷+1 divides   F₃₃₈₂₉₅! 
- Reto Keiser found a new factor:  243 . 2 ⁴⁹⁵⁷³²+1 divides   F₄₉₅₇₂₈! 
- Curtis Cooper found a new factor:  7 . 2 ^2167800+1 divides   F_2167797! 
- Pavlos Saridis found a new factor:  151 . 2 ⁵⁸⁵⁰⁴⁴+1 divides   F₅₈₅₀₄₂! 
It is the opening discovery of 2007, the 5th greatest known prime divisor of a Fermat number, the greatest Fermat divisor with 3 digit k.
As we know Pavlos has been searching for more than 8 years. Very nice Job, Pavlos.
- Asko Vuori found a new factor:  121531 . 2 ³⁰²⁶⁰+1 divides   F₃₀₂₅₆! 

- Jun Tajima found a new factor:  1207 . 2 ⁴¹⁰¹⁰⁸+1 divides   F₄₁₀₁₀₅! 
- Asko Vuori found a new factor:  6213186413 . 2 ⁶⁰⁵+1 divides   F₆₀₀! 
His words: "I have used my laptop Celeron M 1400MHz with WinXP/sp2 home (same as used with F600) When I was counting n=600-699 with Fermat.exe times was dropping 15400 -> 10000 k/sec little by little. Because I don't have net connection in my home, I use library to get online. Testing Fermat.exe with library P4 2800MHz and k/sec was slower than my laptop I was happy with laptop speed. Now n=30000-30999 PRP time is around 6 second per candidate in my laptop. First few months I was happy with that, but then I tested library P4 2800MHz and it used 2.3 second per candidate almost 3 times faster. I was thinking about to quit when k was 100000, but luckily I did not quit. Total speed is around k=k+5000 per week (and +3 hours per week Proth test for those PRPs) So if you have Celeron M in your computer stay n<1000 and use Fermat.exe (regardless of found divisor)"
- Curtis Cooper found a new factor:  27 . 2 ⁶⁷²⁰⁰⁷+1 divides   F₆₇₂₀₀₅! 
- Maximilian Pacher found a new factor:  2018719057 . 2 ¹¹⁶²+1 divides   F₁₁₆₀! 
The factor was found with Fermat.exe.
- Vasily Danilov found a new factor:  1595863660157 . 2 ⁸⁷+1 divides   F₈₃! 
- Michael Eaton found a new factor:  11 . 2 ⁹⁶⁰⁹⁰¹+1 divides   F₉₆₀₈₉₇! 
- Michael Eaton found a new factor:  5731 . 2 ⁶⁰⁰⁸⁴+1 divides   F₆₀₀₇₉! 
The factor was found using fermfact+pfgw+proth.
- Another factor of a Fermat number has been found this year! Jim Fougeron announced today he found a new factor:  211 . 2²⁸⁷³⁸⁸+1 divides F₂₈₇₃₈₄! 
The factor was found using FermFact and NewPGen; PRP test, Primality test and Fermat divisor test using the new alpha WinPGFW(IBDWT).
The whole search (all k's from 157 to 299, N=300000) needed about 4 GHz years of P4 so far, and is still going on. There was about one GHz of initial sieving, prior to the PRP testing.
Congratulations, Jim!
- Payam Samidoost found a new factor:  89.2 ⁴⁷²⁰⁹⁹+1 divides   F₄₇₂₀₉₇!  He informed:
"It was found using Fougeron's FermFact, Woltman's PRP3 and WinPFGW for final Fermat divisibility" It is not only the third greatest Fermat factor known, but also the only one found so far in 2004, almost one year after the last one.
Congratulations, Payam!
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Compiled by Luigi Morelli