probable dud

[Batalov]

... ... Easily sniped.

[VBCurtis]

Originally Posted by mathwiz

Putting this to rest:

[CODE]$ ./pfgw64 -i -V -N -T8 -q"((2^1875230-1)*10^564501+2^1875229-1)"

The problem with doing this is that it achieves the opposite of your hope- rather than show the OP that his ideas are bunk and shouldn't be written out in public, it teaches him that if he asks a dumb enough question, someone will do the calculation work for him to show it's dumb. What he wants is someone to do the computing, and you did his bidding.

We prefer you didn't.

It's cool to post the command you would use (as you also did), so that OP could do it himself if he wasn't so lazy.

[Batalov]

MOD NOTE: next cry of "Fire!" in a cinema theater will be punished by a detention.

People do come to this forum to find news of a, say, next Mersenne prime (which are now pre-screened as PRPs), so the next person who will call their thread "Probable prime" and when asked for reasons why that did such a thing would show a patty cake made out of #2, will get that cake on their face and a two week banishment as well. Call it something else, like "I made up a number", or "asking for an advice" or "I don't know how to check this", or whatever.

[enzocreti]

(2^3680800-1)*10^1108031+2^3680799-1

[enzocreti]

how about this:


(2^1430136-1)*10^430514+2^1430135-1???


I made a stupid mistacke


the candidates have the form


pg(69660+1360476n)




because 69660 is the least N congruent to 215 mod 323 and 0 mod 324 and 6 mod 13

[Batalov]

Originally Posted by enzocreti

...but this is almost surely PRP!
(2^3680800-1)*10^1108031+2^3680799-1

Divisible by 71.

Originally Posted by enzocreti

how about this:
(2^1430136-1)*10^430514+2^1430135-1

Divisible by 14437.

Originally Posted by enzocreti

how about this:
I made a stupid mistacke

Correct.

How about a 2 weeks ban?

[paulunderwood]

Originally Posted by Batalov

Divisible by 71.


Divisible by 14437.


Correct.

How about a 2 weeks ban?

You beat me to it!

[enzocreti]

i did not take into account that N must be 10^m mod 41




let's guess congruent to 1 mod 41




so the candidates must have the form


pg(69660+11992595940n)


impossible to test!

[Batalov]

Originally Posted by enzocreti

i did not take into account that N must be 10^m mod 41

let's guess congruent to 1 mod 41

Do. Not. Guess.
There are no guesses in math.
log₁₀2 is irrational and just happens to be locally close to 0.3 and that is the only reason that there is some local periodicity of modulos w.r.t. n.
This periodicity doesn't hold for larger values of n, so simply stop posting guesses pulled out of your ear (or, as some less polite folks would say, rear).

[storm5510]

Originally Posted by mathwiz

Putting this to rest:

$ ./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.

I have very little interest. These appear to be something simply pulled out of the air. I tried several formats with PFGW. None worked. I did not try the one above. I do not see the point of doing so. End of line...