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Old 2019-09-02, 17:43   #1
Batalov
 
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Default Some new Generalized Cullen and Woodall primes

(off-topic) It looks like PrimeGrid found either a Cullen or a Woodall.
We will likely see it posted in a couple days.

The n is apparently going to be even (in n*bn +/- 1, and n >> 17,000,000, so -- more than a 5 million digiter).
Super!

P.S. Well, this is a generalized Cullen ...slightly less exciting - but still very cool.
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Old 2019-09-02, 18:04   #2
paulunderwood
 
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Quote:
Originally Posted by Batalov View Post
(off-topic) It looks like PrimeGrid found either a Cullen or a Woodall.
We will likely see it posted in a couple days.

The n is apparently going to be even (in n*bn +/- 1, and n >> 17,000,000, so -- more than a 5 million digiter).
Super!
I am looking forward to their publication of their new top 20 prime.
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Old 2019-09-03, 06:49   #3
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It is actually 3,921,539 digits (rank 21) and is being tested at UTM now. The newly discovered prime is 2805222*25^2805222+1

Serge played a part in this by noting that n*b^n+-1 can be tested quicker by testing n*(sqrt(b))^(2*n)+-1, by over 10% when using the LLR program.
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Old 2019-09-04, 00:40   #4
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Quote:
Originally Posted by paulunderwood View Post
It is actually 3,921,539 digits (rank 21) and is being tested at UTM now. The newly discovered prime is 2805222*25^2805222+1

Serge played a part in this by noting that n*b^n+-1 can be tested quicker by testing n*(sqrt(b))^(2*n)+-1, by over 10% 0when using the LLR program.
Once verified (as far as UTM goes) it will be the largest prime discovered this year 2019.

It becomes the largest Generalized Cullen superseding the one discovered last year in March that had 2,913,785 digits.

http://www.primegrid.com/download/gc41-1806676.pdf

Last fiddled with by rudy235 on 2019-09-04 at 00:51
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Old 2019-09-04, 15:56   #5
LaurV
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Yeaaa on the way to 100M digits! Any long way starts with a small step...
Congrats!
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Old 2019-09-05, 04:44   #6
Batalov
 
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Cool

{blowhard mode on}

My GW is still top 1! :-)

{blowhard mode off /}
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Old 2019-09-11, 21:09   #7
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Quote:
Originally Posted by rudy235 View Post
Once verified (as far as UTM goes) it will be the largest prime discovered this year 2019.

It becomes the largest Generalized Cullen superseding the one discovered last year in March that had 2,913,785 digits.

http://www.primegrid.com/download/gc41-1806676.pdf
Finally, we have the official announcement ready.

http://www.primegrid.com/download/gc25-2805222.pdf
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Old 2019-09-17, 12:33   #8
Batalov
 
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A generalized Woodall is on its way, too. (and it is a near-quasi-repdigit, too.)

There could be a couple more in the bag - over a week or so.
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Old 2019-09-30, 21:26   #9
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Quote:
Originally Posted by Batalov View Post
A generalized Woodall is on its way, too. (and it is a near-quasi-repdigit, too.)

There could be a couple more in the bag - over a week or so.
Congrats to you and Ryan for the 3,028,951 digit prime 874208 *2916^874208 - 1

Last fiddled with by paulunderwood on 2019-09-30 at 21:33
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Old 2019-10-26, 19:55   #10
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Congrats ro Serge and Ryan for the 20th largest known prime: 2740879*32^2740879 - 1
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Old 2019-10-27, 05:04   #11
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Quote:
Originally Posted by paulunderwood View Post
Congrats ro Serge and Ryan for the 20th largest known prime: 2740879*32^2740879 - 1

It is the largest Generalized Woodall and with 4125441 digits it is the Third Prime with more than 4 million Digits (and < than 5M)
Congratulations to Ryan and Serge

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