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 Michael Goetz Volunteer moderator
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Congratulations to DeleteNull for finding the 2.6 million digit mega-prime 273809*2^8932416-1 and eliminating k=273809 from the Riesel Problem! 49 k's remain.
This is PrimeGrid's 60th mega prime of 2017, our 195th mega prime overall, and the 15th k eliminated by PrimeGrid from The Riesel Problem. This is also DeleteNull's second mega-prime, as well as the second k he's eliminated from one of the our conjecture projects. (Click here for the full list of DeleteNull's prime discoveries at PrimeGrid.)
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My lucky number is 75898524288+1 |
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RafaelVolunteer tester
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Nice christmas gift... |
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So why does a k get eliminated if a prime is found? Is that the only one that is possible from it?
Edit: pardon my ignorance, I just read about The Riesel Problem and it answered my question.
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JimBHonorary cruncher
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So why does a k get eliminated if a prime is found? Is that the only one that is possible from it?
http://www.prothsearch.com/rieselprob.html
or
http://www.primegrid.com/forum_thread.php?id=1731 |
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Congratulations to DeleteNull for finding the 2.6 million digit mega-prime 273809*2^8932416-1 and eliminating k=273809 from the Riesel Problem! 49 k's remain.
Many thanks to all who have helped to make this possible! I am the lucky one who got this special workunit to eleminate that k.
And 49 k remain, so there will be other lucky (and patient) finders in the future ;)
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DeleteNull |
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dukebgVolunteer tester
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Congratulations!
That's pretty amazing. More than 3 years since a k was eliminated in TRP last time! |
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Congratulations!! |
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My congrats as well. |
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Well done ! |
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Big congrats ! |
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Dave
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Another +1 well done - nice achievement to (nearly) end the year. |
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Another +1
Nope, it's a -1 (Riesel), not Proth ;)
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Twitter: IainBethune
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3073428256125*2^1290000-1 is Prime! |
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Another +1
Nope, it's a -1 (Riesel), not Proth ;)
Ha ha.
But it depends on the perspective. If you write the candidate as:
N = k·2^n - 1
then you are right, we see a minus one.
But if you express instead, in terms of N, the number that is smooth to factor, that is N + 1, so for example in the help for PFGW, you can see:
-t currently performs a deterministic test. By default this is an N-1
test, but N+1 testing may be selected with '-tp'. N-1 or N+1 is
factored, and Pocklington's or Morrison's Theorem is applied. If 33%
size of N prime factors are available, the Brillhart-Lehmer-Selfridge
test is applied for conclusive proof of primality. If less than 33%
is factored, this test provides 'F-strong' probable primality with
respect to the factored part F.
And in Caldwell's Primality Proving pages, the term N+1 test is used in the same sense.
So Riesel is an N+1 test.
+1 to me.
/JeppeSN |
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4th place in Riesel primes top!
Very nice!
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(252^6548-1)^2-2 is prime! Small, but mine.
134137784^32768+1(DC)
107853608^8192+1(DC)
10465966^16384+1(DC)
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That is what I call "the prime" :)
Congratulations!
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92*10^1439761-1 REPDIGIT PRIME :) :) :)
314187728^131072+1 GENERALIZED FERMAT
31*332^367560+1 CRUS PRIME
Proud member of team Aggie The Pew. Go Aggie! |
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