mersenneforum.org theory on Mersenne primes ?
 Register FAQ Search Today's Posts Mark Forums Read

2010-11-14, 18:19   #89
CRGreathouse

Aug 2006

3×52×79 Posts

They're used in efficient algorithms (because modular reduction can be done with shifts and subtraction), especially in cryptology.

Quote:
 Originally Posted by 3.14159 I wish to know from which website you are pasting these from.
My own knowledge. I don't know of a site collecting all this information together. As far as I know, this thread is the only place on the Internet that does that.

 2010-11-14, 19:01 #90 3.14159     May 2010 Prime hunting commission. 24·3·5·7 Posts Don't you mean, these forums in general?
2010-11-14, 19:03   #91
CRGreathouse

Aug 2006

3×52×79 Posts

They can be used to calculate the convolution or correlation of 2D images in parallel.

Quote:
 Originally Posted by 3.14159 Don't you mean, these forums in general?
No, I meant this particular thread. If you know of other threads giving this kind of information, let me know! I'd be happy to pool my information with others.

2010-11-14, 22:29   #92
science_man_88

"Forget I exist"
Jul 2009
Dumbassville

20C016 Posts

Quote:
 Originally Posted by CRGreathouse They can be used to calculate the convolution or correlation of 2D images in parallel. No, I meant this particular thread. If you know of other threads giving this kind of information, let me know! I'd be happy to pool my information with others.
Displaying 1-10 of 347 results found. for A000043
Displaying 1-10 of 368 results found. for mersenne prime -A000043
Displaying 1-10 of 234 results found. for "mersenne prime" -A000043

 2010-11-14, 22:34 #93 science_man_88     "Forget I exist" Jul 2009 Dumbassville 100000110000002 Posts A053648 has a possible term missing 31 when listing of from 131071 oh it's already listed under 31 dah lol. Last fiddled with by science_man_88 on 2010-11-14 at 22:44
2010-11-15, 01:39   #94
CRGreathouse

Aug 2006

3·52·79 Posts

The factorization of small Mersenne numbers resulted in a significant speedup for Jan Feitsma's calculation of the pseudoprimes.

Quote:
 Originally Posted by science_man_88 Displaying 1-10 of 347 results found. for A000043 Displaying 1-10 of 368 results found. for mersenne prime -A000043 Displaying 1-10 of 234 results found. for "mersenne prime" -A000043
I'm pretty familiar with the OEIS, but much/most of the information I've listed so far isn't there as far as I know.

 2010-11-15, 01:51 #95 3.14159     May 2010 Prime hunting commission. 24×3×5×7 Posts I have a challenge for you; Why don't you set off and find me a composite number which passes the BPSW test? Good luck! Last fiddled with by 3.14159 on 2010-11-15 at 01:51
2010-11-15, 04:54   #96
CRGreathouse

Aug 2006

3×52×79 Posts

If m is a Mersenne prime, then $\sigma(m+1)-\sigma(m)=m.$

Quote:
 Originally Posted by 3.14159 I have a challenge for you; Why don't you set off and find me a composite number which passes the BPSW test? Good luck!
There's a $620 bounty for that. What's more, there is a (finite) collection of numbers chosen in such a fashion that it is believed that a product of certain terms is a BPSW-pseudoprime. So that's something of a head start. Also, the "cheap third author" as I believe Pomerance referred to himself, has considered raising his share of the prize from$20, so you might even get more out of it than \$620.

Last fiddled with by CRGreathouse on 2010-11-15 at 04:57

2010-11-16, 17:29   #97
science_man_88

"Forget I exist"
Jul 2009
Dumbassville

20C016 Posts

Quote:
 Originally Posted by science_man_88 I was saying that numbers of a specific sumdigits like 2 can be found to be possible in one case of 5mod9*8mod9 = 4mod9 so 2*2mod9 =4mod9 + 1 =5 so k=1 is an answer for a 5mod9 if we look for 8mod9 8*2mod9+1= 8mod9 so k=4 is a possibility in this case it works for 11 which is sumdigits(x)=2
anyone actually figure me out yet ? since this was a while ago i figured your minds need refreshing.

2010-11-16, 20:26   #98
CRGreathouse

Aug 2006

3·52·79 Posts

Let M be an p X p matrix with 1s down the first column, 2s down the main diagonal (except the top-left), -1s down the subdiagonal (again, except the element in the first column), and 0s elsewhere. Then det M is a Mersenne number. [Janjic]

Quote:
 Originally Posted by science_man_88 anyone actually figure me out yet ? since this was a while ago i figured your minds need refreshing.
I don't understand it. If you write it out formally there may be a chance that someone will solve it.

2010-11-16, 20:30   #99
science_man_88

"Forget I exist"
Jul 2009
Dumbassville

26×131 Posts

Quote:
 Originally Posted by CRGreathouse Let M be an p X p matrix with 1s down the first column, 2s down the main diagonal (except the top-left), -1s down the subdiagonal (again, except the element in the first column), and 0s elsewhere. Then det M is a Mersenne number. [Janjic] I don't understand it. If you write it out formally there may be a chance that someone will solve it.
basically I'm trying to use the sumdigit(p) to determine k values to check if that helps it should be useful in finding factors.

 Similar Threads Thread Thread Starter Forum Replies Last Post carpetpool Miscellaneous Math 3 2017-08-10 13:47 emily Math 34 2017-07-16 18:44 Nick Math 4 2017-04-01 16:26 Nick Number Theory Discussion Group 0 2016-12-03 11:42 optim PrimeNet 13 2004-07-09 13:51

All times are UTC. The time now is 17:48.

Fri Sep 25 17:48:20 UTC 2020 up 15 days, 14:59, 0 users, load averages: 1.68, 1.61, 1.51