A yuge number - Page 3

axn · 2018-12-08, 08:31

Quote:

Originally Posted by a1call

IINM That only works on the Linux versions.

Possibly, if you installed using Windows installer, the feature is not enabled by default. But I (almost) always use the standalone executable, and they come with this enabled.

Code:

GP/PARI CALCULATOR Version 2.12.0 (development 22943-2eb50d55b)
  amd64 running mingw (x86-64/GMP-6.1.2 kernel) 64-bit version
  compiled: Aug 22 2018, gcc version 7.3-win32 20180506 (GCC)
                    threading engine: single
         (readline v6.2 enabled, extended help enabled)

enzocreti · 2018-12-09, 20:40

I conjectured that there is no probable prime 6 mod 7 of the form (2^k-1)*10^d+2^(k-1)-1. How can I test this conjecture up to at least k=1.000.000?

science_man_88 · 2018-12-09, 20:43

Quote:

Originally Posted by enzocreti

I conjectured that there is no probable prime 6 mod 7 of the form (2^k-1)*10^d+2^(k-1)-1. How can I test this conjecture up to at least k=1.000.000?

find the pattern of when it can be 6 mod 7 and test through sets of conditions. show them failing the testing to be probable primes etc.

enzocreti · 2018-12-10, 07:31

Quote:

Originally Posted by science_man_88

find the pattern of when it can be 6 mod 7 and test through sets of conditions. show them failing the testing to be probable primes etc.

According to a mathexchange user, there shouldn't be any probable prime 6 mod 7 up to k=800.000
I wonder how much far we should arrive for finding one!

Batalov · 2018-12-10, 07:47

According to a bearded guy who was pushing a shopping cart full of tin cans, the number you are looking for is around 937,500.
But why should one be gullible enough to listen to that guy?
...Or that other guy that you mentioned?

enzocreti · 2018-12-10, 07:50

Quote:

Originally Posted by Batalov

According to a bearded guy who was pushing a shopping cart full of tin cans, the number you are looking for is around 937,500.
But why should one be gullible enough to listen to that guy?
...Or that other guy that you mentioned?

I don't understand...i trust him...he found also a probable prime of this form for k=541456.

enzocreti · 2018-12-10, 11:18

palindromic prime 111010111 divides (2^3343663-1)*10^1006543+2^3343662-1!!!

enzocreti · 2018-12-10, 12:28

besides 111010111 and 691, what are the other factors of this huge number?

MisterBitcoin · 2018-12-17, 10:40

Quote:

Originally Posted by enzocreti

besides 111010111 and 691, what are the other factors of this huge number?

Quote:

Originally Posted by axn

No factors till 32*10^9. Quitting my attempt.

According to axn´s post, the status of the number is unknown.
As expected, it is not an PRP.

Code:

(2^7891456-1)*10^2375565+2^7891455-1 is composite: RES64: [8DA21E99C6B92C74] (790809.4526s+0.6214s)

Do me a favor, and double check this result. Check this forum, you will find all what you need. No tips.

2018-12-09, 20:40	#24
enzocreti Mar 2018 2×5×53 Posts	HOW TO REACH EXPONENT 1 MILLION I conjectured that there is no probable prime 6 mod 7 of the form (2^k-1)10^d+2^(k-1)-1. How can I test this conjecture up to at least k=1.000.000? Last fiddled with by enzocreti on 2018-12-09 at 20:40*

2018-12-10, 11:18	#29
enzocreti Mar 2018 2×5×53 Posts	palindromic prime palindromic prime 111010111 divides (2^3343663-1)*10^1006543+2^3343662-1!!!

2018-12-10, 12:28	#30
enzocreti Mar 2018 1000010010₂ Posts	factors besides 111010111 and 691, what are the other factors of this huge number?

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2018-12-10, 07:47	#27
Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 3⁶×13 Posts	According to a bearded guy who was pushing a shopping cart full of tin cans, the number you are looking for is around 937,500. But why should one be gullible enough to listen to that guy? ...Or that other guy that you mentioned?