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Old 2014-02-03, 04:49   #1
paulunderwood
 
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Lightbulb Why NeRDs_360360?

Why did I choose 10^360360-10^k-1?

360360 = 2*2*2*3*3*5*7*11*13

For small primes p, 10^((p-1)*a)==1 (mod p), and so 10^360360-10^k-1 is not divisible by p. Consequently, after sieving, there is about 15% of the range left and we expect to find about 3 primes in the provable range k=90090-360360.
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Old 2014-02-03, 08:19   #2
Batalov
 
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It would have been better to chose a>1290000*log102 for 10^a-10^k-1. With a=360360, the found primes will be swept away in about a year by the TwinGen-ial deluge. a=17#, perhaps?
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Old 2014-02-03, 08:33   #3
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Quote:
Originally Posted by paulunderwood View Post
Consequently, after sieving, there is about 15% of the range left and we expect to find about 3 primes in the provable range k=90090-360360.
What's the total number of candidates left after sieving?
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Old 2014-02-03, 17:08   #4
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42320 candidates were left in the range 90000-360360.

Chuck Lasher is crunching 3/19 of this. Thomas, you are crunching 1/19. I crunched some. The rest was put up, ready for others to crunch -- 1 or 2 weeks per file folks.
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Old 2014-02-03, 17:10   #5
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Quote:
Originally Posted by Batalov View Post
It would have been better to chose a>1290000*log102 for 10^a-10^k-1. With a=360360, the found primes will be swept away in about a year by the TwinGen-ial deluge. a=17#, perhaps?
These may be "swept away" from the top5000, but they should stay on the near-repdigit table.

I have exponents 388080 and 471240 sieved.

Last fiddled with by paulunderwood on 2014-02-03 at 17:29
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