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Old 2013-03-29, 03:44   #1
ixfd64
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"Danny"
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Default How unlucky have I been?

I just realized I've completed 218 P-1 assignments without finding a factor. Yikes.

Anyone ever had a longer dry spell?

Last fiddled with by ixfd64 on 2013-03-29 at 03:46
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Old 2013-03-29, 03:48   #2
petrw1
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Quote:
Originally Posted by ixfd64 View Post
I just realized I've completed 218 P-1 assignments without finding a factor. Yikes.

Anyone ever had a longer dry spell?
About 3 times that many rounds of golf and not a single hole-in-one!
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Old 2013-03-29, 04:02   #3
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Quote:
Originally Posted by ixfd64 View Post
I just realized I've completed 218 P-1 assignments without finding a factor. Yikes.
Can I guess 48 of the numbers?
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Old 2013-03-29, 09:14   #4
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Quote:
Originally Posted by ixfd64 View Post
I just realized I've completed 218 P-1 assignments without finding a factor. Yikes.

Anyone ever had a longer dry spell?
I don't recall how many, but some years ago, I went about 5 months without finding any. I think I was doing about one per day, so that wouldn't be as many as yours.

I recommend you try some torture testing. Perhaps your hardware is beginning to flake. Otherwise just carry on. Every P-1 you do is a P-1 that someone else won't have to do, and which, if they did, would have been done a lot less efficiently that you did it.
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Old 2013-03-29, 12:01   #5
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Assuming an average 3.5% chance of success per test (and assuming I'm calculating correctly), there was only a 1 in ~2400 probability that none of the 218 would result in a factor. You should've expected around 7.8 factors. Either you've been VERY unlucky, or your hardware is unstable.

Last fiddled with by Mini-Geek on 2013-03-29 at 12:06
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Old 2013-03-29, 14:17   #6
petrw1
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Default 126 is my worst

In my life I have done 2,925 P-1 (on several PC's).
My longest streak was 126 with no factors.
But I also had a streak of 3 in a row and 4 out of 5.
182 total factors found: 6.22%
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Old 2013-03-29, 16:03   #7
ixfd64
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Quote:
Originally Posted by Mini-Geek View Post
Assuming an average 3.5% chance of success per test (and assuming I'm calculating correctly), there was only a 1 in ~2400 probability that none of the 218 would result in a factor. You should've expected around 7.8 factors. Either you've been VERY unlucky, or your hardware is unstable.
I doubt the latter is the case, considering most of those results are from three different computers (I have four doing P-1 at the moment).
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Old 2013-03-29, 16:08   #8
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As a test, run an exponent that has a P-1 factor already found?

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Old 2013-03-29, 17:45   #9
petrw1
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Quote:
Originally Posted by ixfd64 View Post
I doubt the latter is the case, considering most of those results are from three different computers (I have four doing P-1 at the moment).
No offense; just checking:

Doing Stge 1 AND 2?
Enough RAM allocated to give you an estimate of at least 4% or more?

Your resul last 365 days are only about 2.7%. Seems low.
Could be one of the 2 reasons above OR just from your unlucky streak.

But then your lifetime is over 6%. That's good.

Last fiddled with by petrw1 on 2013-03-29 at 17:52
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Old 2013-03-29, 18:09   #10
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Quote:
Originally Posted by Xyzzy View Post
As a test, run an exponent that has a P-1 factor already found?

If you want to run some tests, here are ten which had a factor found by P-1'ing. Set your PFactor line to have the "Factored To" value to be no more than the last column.

Code:
+----------+---------------+--------+
| Exponent | BitLevel      | FactTo |
+----------+---------------+--------+
| 54911783 | 58.3215560913 |     58 | 
| 58910237 | 64.6313400269 |     64 | 
| 58726133 | 65.4111557007 |     65 | 
| 52733041 | 68.8312835693 |     68 | 
| 51247057 | 70.7599105835 |     70 | 
| 48609521 | 70.9801712036 |     70 | 
| 52303133 | 71.0078811646 |     71 | 
| 48533731 | 71.0444488525 |     71 | 
| 47254231 | 71.0491561890 |     71 | 
| 50556529 | 71.0697021484 |     71 | 
+----------+---------------+--------+
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Old 2013-03-29, 18:18   #11
ATH
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Looking at the lifetime stats on the P-1 top producer page:

Top 100 producers have 25,681 successes in 536,894 attempts ~ 4.8% success rate

Top 1000 producers have 34,632 successes in 794,810 attempts ~ 4.4% success rate

Looking at all the 9,834 producers: 37,309 successes in 842,985 attempts ~ 4.4% success rate


Using 4.4% for 218 failed attempts: 0.956^218 ~ 0.0055 % or 1 in 18204.

Last fiddled with by ATH on 2013-03-29 at 18:27
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