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 2020-08-31, 11:27 #1 enzocreti   Mar 2018 17·31 Posts probable dud ((2^1875230-1)*10^564501+2^1875229-1) has small factors? I don't know...
 2020-08-31, 13:47 #2 mathwiz   Mar 2019 12710 Posts Well, have you PRP tested this with PFGW? Or are you asking us to do it for you? Last fiddled with by enzocreti on 2020-08-31 at 13:51
2020-08-31, 13:50   #3
retina
Undefined

"The unspeakable one"
Jun 2006
My evil lair

23×3×5×72 Posts

Quote:
 Originally Posted by mathwiz Or are you asking us to do it for you?
It wouldn't be much different from Google demanding everyone do their job for them with the captcha images.

2020-08-31, 13:52   #4
enzocreti

Mar 2018

52710 Posts

Quote:
 Originally Posted by mathwiz Well, have you PRP tested this with PFGW? Or are you asking us to do it for you?

Unfortunally my computer is broken!

 2020-08-31, 15:08 #5 CRGreathouse     Aug 2006 2×2,969 Posts So what makes you think it is a probable prime?
2020-08-31, 15:34   #6
storm5510
Random Account

Aug 2009
U.S.A.

69F16 Posts

Quote:
 Originally Posted by enzocreti ((2^1875230-1)*10^564501+2^1875229-1) has small factors?
This appears to be a request for somebody with a lot of cores to run it. I am not sure PFGW could handle it in this form. Then again, maybe it could. Any person trying may need several generations of descendants to see it done. It might have to look something like this though:

Quote:
 (((2^1875230-1)*10^564501+2)^1875229-1)
I am not sure how PFGW handles parenthetical's or if it will accept them at all.

2020-08-31, 15:43   #7
enzocreti

Mar 2018

17·31 Posts

Quote:
 Originally Posted by CRGreathouse So what makes you think it is a probable prime?
Pg(69660) is prime

69660 is multiple of 215 and congruent to 215 mod 323...it is also 6 mod 13... using wolphram numbers of this form are 69660+xn where x i don't remember what it is.

69660 is the least number N such that N is 215 mod 323, N is 0 mod 215 and N is 6 mod 13...
then you have other values using Chinese remainder theorem

 2020-08-31, 15:43 #8 Uncwilly 6809 > 6502     """"""""""""""""""" Aug 2003 101×103 Posts 17·523 Posts
2020-08-31, 15:52   #9
mathwiz

Mar 2019

127 Posts

Quote:
 Originally Posted by enzocreti Unfortunally my computer is broken!
so how/where did you somehow come up with this number?

2020-08-31, 17:36   #10
CRGreathouse

Aug 2006

2·2,969 Posts

Quote:
 Originally Posted by enzocreti Pg(69660) is prime 69660 is multiple of 215 and congruent to 215 mod 323...it is also 6 mod 13... using wolphram numbers of this form are 69660+xn where x i don't remember what it is. 69660 is the least number N such that N is 215 mod 323, N is 0 mod 215 and N is 6 mod 13... then you have other values using Chinese remainder theorem
I agree that 69660 == chinese([Mod(215,323), Mod(0,215), Mod(6,13)]), and I'm prepared to assume that Pg(69660) is prime. But why should that make us think that

((2^1875230-1)*10^564501+2^1875229-1)

is likely to be prime?

2020-08-31, 17:59   #11
mathwiz

Mar 2019

11111112 Posts

Quote:
 Originally Posted by CRGreathouse So what makes you think it is a probable prime?
Putting this to rest:

Code:
\$ ./pfgw64 -i -V -N -T8 -q"((2^1875230-1)*10^564501+2^1875229-1)"
PFGW Version 4.0.0.64BIT.20190528.x86_Dev [GWNUM 29.8]

Generic modular reduction using generic reduction AVX-512 FFT length 384K, Pass1=1K, Pass2=384, clm=1, 8 threads on A 3750464-bit number
Resuming at bit 1480000
((2^1875230-1)*1....501+2^1875229-1) is composite: RES64: [52E573162A497910] (5201.6106s+0.0149s)
As to whether the factors are small, I have neither the time nor interest to care.

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