![]() |
|
|
#375 |
|
"Forget I exist"
Jul 2009
Dumbassville
26×131 Posts |
well I never knew about general forms meaning anything different anyway if i retract my 5iii statement the above is what you have conveyed to me from what posts i can find still.
|
|
|
|
|
|
#376 | |
|
May 2010
Prime hunting commission.
24×3×5×7 Posts |
Quote:
The largest so far is 219561 digits, submitted by Batalov. Second largest is 118995 digits, submitted by me, followed by Max's 109443-digit prime for the -1 analogues of the Generalized Proth numbers. Last fiddled with by 3.14159 on 2010-09-07 at 18:54 |
|
|
|
|
|
|
#377 |
|
"Forget I exist"
Jul 2009
Dumbassville
26·131 Posts |
please note all the highlighting of the important words.
Last fiddled with by science_man_88 on 2010-09-07 at 18:55 |
|
|
|
|
|
#378 |
|
May 2010
Prime hunting commission.
110100100002 Posts |
I remember the good old days, four or so months ago.. When I became excited about finding a now measly 4000-digit prime. Fun times?
I think I remember the sequence of records I have made (Length of prime found in decimal digits): ≤ 1000, 2986, 4457, 5423, 8608, 13050, 27507, 40078, 77285, 118995, etc.. Sadly, 25-50% of them were already well-known cases. Only the last four are of my own discovery for sure. Since I snapped personal records by about 40k digits for about 2x in a row, I will search for a 165k-digit prime. Using b = 2; n = 552600; I measured the odds as 1 in 7366 when I removed 25 out of 26 candidates, or 96.1% of the candidates. To be safe, and quick, the k-range is 20 times the odds. ... If the odds are 1 in 7366, and there are 3460 candidates left; Does that mean I have only a 47% chance of finding a prime? And the sieve actually decreased my odds of finding a prime? In that case; I'm going to increase the range by a factor of 15. Last fiddled with by 3.14159 on 2010-09-07 at 19:20 |
|
|
|
|
|
#379 |
|
Mar 2006
Germany
22·727 Posts |
|
|
|
|
|
|
#380 | |
|
May 2010
Prime hunting commission.
69016 Posts |
Quote:
|
|
|
|
|
|
|
#381 |
|
"Forget I exist"
Jul 2009
Dumbassville
26·131 Posts |
sorry for upsetting you Pi I just don't understand most of what I read some days.
all I can think of is something like k*b^n+c form for "general number" that fits one of the ones on the list. Last fiddled with by science_man_88 on 2010-09-07 at 19:33 |
|
|
|
|
|
#382 |
|
"Forget I exist"
Jul 2009
Dumbassville
838410 Posts |
okay well I have you stating they are all special form primes hence no primes on your list. yet all primes with a certain length should fit your list.
Last fiddled with by science_man_88 on 2010-09-07 at 19:31 |
|
|
|
|
|
#383 |
|
Mar 2006
Germany
22×727 Posts |
Sorry, but the above number 2077756847362348863128179 is a cofactor of these numbers:
(4^109-1)/3, 2^218-1, 2^109+1, 2*2^108+1, 2^110+2, 2*2^109+2, 2^111+4, 2^110+4, 2^2507+1, 2^5014-1, (4^2507-1)/3, 2^10028-1 and perhaps much more. So it has a special form (cofactor of a Mersenne number for example!) and you are not able to notice this, so you have to specify your 'general number' type! |
|
|
|
|
|
#384 | |
|
Aug 2006
3×1,993 Posts |
Quote:
I don't know how you'd come to that conclusion. In rough terms: You're starting with C candidates with probability p of being prime. You sieve out a fraction (S-1)/S of the candidates, giving you C/S remaining candidates with probability pS of being prime. The expectations remain the same. |
|
|
|
|
|
|
#385 |
|
Mar 2006
Germany
22·727 Posts |
And that's why this type is ridiculous!
You can't spot a number 'general' or random or special! Sorry and thanks CRG! Sorry: You lost your 1# place! Thanks: to show this! Last fiddled with by kar_bon on 2010-09-07 at 19:37 |
|
|
|
![]() |
| Thread Tools | |
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Prime posting thread, part 2. (With a catch.) | 3.14159 | Miscellaneous Math | 55 | 2010-11-19 23:55 |
| Tiny range request .... 555.1M | petrw1 | LMH > 100M | 1 | 2010-07-13 15:35 |
| Other primes thread | nuggetprime | No Prime Left Behind | 32 | 2009-10-21 21:48 |
| Error: tiny factoring failed | 10metreh | Msieve | 26 | 2009-03-08 23:28 |
| Tiny error on nfsnet pages. | antiroach | NFSNET Discussion | 1 | 2003-07-08 00:27 |