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Old 2017-03-22, 03:32   #188
davar55
 
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Actually I consider the work put into this sequence and the discovery
of the a(20) prime very valuable. Perhaps my expectations for an
"important result" were already sufficiently satisfied.
It certainly is a very interesting anomalously large prime.
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Old 2017-03-25, 09:44   #189
J F
 
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Quote:
Originally Posted by davar55 View Post
It certainly is a very interesting anomalously large prime.
What is 'anomalously large'? You can approximate the probability
that the sequence from a starting value will yield no prime up
to some digit count. The chance to 'survive' to 300K digits is
order of magnitude 0.5%. I got 11 >300K with the smallish sample
size of 1666, so far that seems sane enough to me.
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Old 2017-05-19, 13:34   #190
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Is a(20) longer than 613373?
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Old 2017-05-20, 06:27   #191
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Quote:
Originally Posted by davar55 View Post
Is a(20) longer than 613373?
613373 has only six digits.
a(20) is definitely longer!
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Old 2017-05-23, 13:23   #192
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Quote:
Originally Posted by Batalov View Post
613373 has only six digits.
a(20) is definitely longer!
In character length, "a(20)" has only five characters.

But clarifying my question, has a(20) more than 613373 decimal digits?
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Old 2017-06-26, 15:05   #193
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Actually, is a(20) well defined until or unless a prime is found at that location?
So the previous post was just a request for a progress report.
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Old 2017-06-26, 22:12   #194
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Progress report: #20 somewhere around 750K digits, no PRP yet
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Old 2017-06-27, 13:25   #195
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Thanks. Great work. This result is surprisingly tantalizing.
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Old 2017-06-27, 15:48   #196
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I stopped at 750k digits searching for "standard" pi primes starting at 3.1415. No new primes before or after the 613373 digit one.
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Old 2017-06-27, 16:25   #197
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Quote:
Originally Posted by ATH View Post
I stopped at 750k digits searching for "standard" pi primes starting at 3.1415. No new primes before or after the 613373 digit one.
Did you sieve beyond 750k? If so, you should consider posting the remaining terms.
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Old 2017-06-27, 16:33   #198
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Yes, I sieved up to 1 million digits, and I have actually still been sieving sometimes on computers at work. I'm on vacation now, I will try to sort out how far I got and post in 1-2 weeks.
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