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 2019-03-21, 13:21 #210 LaurV Romulan Interpreter     Jun 2011 Thailand 24×571 Posts 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.
 2019-03-21, 13:58 #211 paulunderwood     Sep 2002 Database er0rr 1101110010102 Posts 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
2019-03-21, 15:03   #212
davar55

May 2004
New York City

102108 Posts

Quote:
 Originally Posted by LaurV 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.)

 2019-03-21, 16:33 #213 danaj   "Dana Jacobsen" Feb 2011 Bangkok, TH 2×3×151 Posts 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.
2020-02-18, 21:05   #214
rogue

"Mark"
Apr 2003
Between here and the

6,163 Posts

Quote:
 Originally Posted by J F #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%.

 2020-08-15, 19:31 #215 davar55     May 2004 New York City 423210 Posts What is the status of a(20)? Will it reach 10^6 soon?
2020-08-15, 22:55   #216
rogue

"Mark"
Apr 2003
Between here and the

616310 Posts

Quote:
 Originally Posted by davar55 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.

 2020-12-26, 01:54 #217 davar55     May 2004 New York City 23×232 Posts Oh I see. I thought of a different possibility.

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