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Old 2019-03-21, 13:21   #210
LaurV
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My computer can do it in a quarter of that time. In fact, it can do it in a tenth of that time. In fact, it can do it in an infinite-small fraction of that time.
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Old 2019-03-21, 13:58   #211
paulunderwood
 
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Code:
? floor((31.4*10^12/10^4)^4)
97211712160000000000000000000000000000
This is the number of core years to prove a 31.4 trillion digit number with Primo. Of course you would need to have a great big system, be prepared to backtrack over millenia, and expect Marcel (and decendants-of-Marcel) to build the tables. If you can use enough atoms to store the step information and the certificate without creating a black hole you will be doing well

Last fiddled with by paulunderwood on 2019-03-21 at 14:08
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Old 2019-03-21, 15:03   #212
davar55
 
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Quote:
Originally Posted by LaurV View Post
My computer can do it in a quarter of that time. In fact, it can do it in a tenth of that time. In fact, it can do it in an infinite-small fraction of that time.
Ha ha.

(Although an "infinite-small fraction" of an infinite time span
might be infinite or finite itself.)
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Old 2019-03-21, 16:33   #213
danaj
 
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Using GMP, assuming it all fits in memory and GMP scales fine, it's only 1.8 billion years to finish BPSW.

My single threaded Primo calculation came out to only exp( 4.01 * (log(3140000000000)-log(2000)) + log(2313.8) ) / 60 / 60 / 24 / 365.25 = 550528055283376774128261550300497 years. Based on timings from a few years ago to compute various sizes up to 2000 digits, and assuming of course that we can just handwave practicality and scaling.

AKS using Bernstein Theorem 4.1, about 5e59 years. But parallelism is trivial, so that will really help a lot.
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Old 2020-02-18, 21:05   #214
rogue
 
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Quote:
Originally Posted by J F View Post
#20 at 833K digits atm, no PRP.
Quick (and very rough) approximation that a random pick
with n decimal digits is prime: 1 : 2.3n
Chance to find none between 750K and 1M is around 90%.
Any updates on this search?
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Old 2020-08-15, 19:31   #215
davar55
 
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What is the status of a(20)? Will it reach 10^6 soon?
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Old 2020-08-15, 22:55   #216
rogue
 
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Quote:
Originally Posted by davar55 View Post
What is the status of a(20)? Will it reach 10^6 soon?
With no activity since March of 2018, I suspect the user gave up.
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