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Old 2012-11-25, 16:17   #45
James Heinrich
 
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"James Heinrich"
May 2004
ex-Northern Ontario

32·19·23 Posts
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As I'm working slowly through the ranges I'm starting to see some odd behaviour. Specifically, some ranges (of 10-million exponents) are finding approximately 15000 factors but other close ranges are only finding about half of that. For example:
Code:
Range   Candidates    Factored    Unfactored   Factors in 20000<k<100000
2130M       464,860     156,532       308,328     15,644 
2140M       465,831     154,327       311,504     13,301 
2150M       465,334     147,582       317,752      7,336 
2160M       465,180     147,187       317,993      7,204
The lack of newly-found factors is not because factors have been previously found, you can see that there is really just fewer candidates factored in some ranges. I thought perhaps my code was misbehaving (which it yet might be), but running in other ranges there has been no dropoff in factor rate:
Code:
Range   Candidates    Factored    Unfactored   Factors in 20000<k<100000
1050M       481,207     169,206       312,001     16,183 
1060M       481,433     164,587       316,846     16,218 
1070M       480,645     164,706       315,939     16,263 
1080M       481,153     164,910       316,243     16,275 
                                    
1590M       471,866     160,013       311,853     15,984 
1600M       471,784     159,748       312,036     16,124 
1610M       471,178     159,317       311,861     15,697 
1620M       471,758     159,554       312,204     15,660
Any ideas why this might be?

edit: the dropoffs are visible in the graph, notably the sharp drop around 2140M as noted above.

Last fiddled with by James Heinrich on 2012-11-25 at 16:39 Reason: fixed: ranges are 10-million, not 1-million
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