mersenneforum.org  

Go Back   mersenneforum.org > Search Forums

Showing results 1 to 25 of 25
Search took 0.01 seconds.
Search: Posts Made By: vector
Forum: Math 2008-03-22, 19:52
Replies: 15
Views: 1,941
Posted By vector
Since this question deals with subset sums I...

Since this question deals with subset sums I might as well as this here...

Is it easier to solve subset sum problems whose sets can be partitioned into two, similarly sized, super increasing sets....
Forum: Math 2008-03-07, 16:14
Replies: 15
Views: 1,941
Posted By vector
Why are you taking logarithms of the congruences?...

Why are you taking logarithms of the congruences? This will not accomplish anything. You cant represent and apply the Chinese remainder theorem operation logarithmically, your algorithm would just...
Forum: Math 2008-03-06, 03:39
Replies: 15
Views: 1,941
Posted By vector
Joining/merging means using the Chinese remainder...

Joining/merging means using the Chinese remainder theorem on congruences (a1 mod b1) and (a2 mod b2) to get another congruence of the form (a3 mod b1*b2).

For a congruence (A mod B) or (3 mod 11)...
Forum: Math 2008-03-05, 23:47
Replies: 15
Views: 1,941
Posted By vector
Modular Subset "Product" Problem

Is there info on how to solve this type of problem somewhere?

Suppose you have a set of congruences A[i] mod B[i] such that A[i] is a random integer and B[i] is a random prime. (the primes are...
Forum: Miscellaneous Math 2007-12-15, 19:59
Replies: 10
Views: 2,333
Posted By vector
I wrote it because I thought it would result in...

I wrote it because I thought it would result in faster multiplication than the bigInteger multiplication method. It is supposed to break the large multiplication problem into many small...
Forum: Miscellaneous Math 2007-12-15, 14:12
Replies: 10
Views: 2,333
Posted By vector
Why what?

Why what?
Forum: Miscellaneous Math 2007-12-15, 12:50
Replies: 10
Views: 2,333
Posted By vector
Ok I commented the code. :rolleyes: import...

Ok I commented the code. :rolleyes:

import java.math.BigInteger;//imports
import java.util.ArrayList;
import java.util.Random;

public class Main {
//global vars
public static...
Forum: Miscellaneous Math 2007-12-15, 10:18
Replies: 10
Views: 2,333
Posted By vector
New Multiplication Algorithm

I just coded a new multiplication algorithm which slower than trial multiplication :smile:
It is in java code.


import java.math.BigInteger;
import java.util.ArrayList;
import...
Forum: Math 2007-12-07, 22:35
Replies: 10
Views: 1,236
Posted By vector
I answered that already. You just have to check...

I answered that already. You just have to check whether p-1 is an element generated by 2^x mod p. Also, since p-1 is a special case of being -1 mod p you don't even have to compute the order of p-1...
Forum: Math 2007-12-07, 18:18
Replies: 10
Views: 1,236
Posted By vector
I think that to prove that a particular prime...

I think that to prove that a particular prime will never divide 2^n+1 you need to show that 2^n+1 mod p never equals 0. Or that 2^n mod p is never equal to p-1. So if p-1 is never generated by base...
Forum: Math 2007-12-02, 10:26
Replies: 9
Views: 1,546
Posted By vector
3^4 mod 11=5; ord(3)=5; 3rd root inverting...

3^4 mod 11=5; ord(3)=5;
3rd root inverting exponent= 3*exponent=1 mod 5, inverting exponent=2;
so (3^2)^4 =5^2 mod 11;
therefore 9^x = 3 mod 11;
and 3^x = 5 mod 11;
also ord(9)=5;
So...
Forum: Math 2007-12-02, 02:40
Replies: 9
Views: 1,546
Posted By vector
Yeah I realized this couple of minutes after...

Yeah I realized this couple of minutes after posting. A correct simplification is that ord(b) must be divisible ord(a) without leaving a remainder.

Anyway it turned out that this did not help...
Forum: Miscellaneous Math 2007-12-01, 14:43
Replies: 5
Views: 1,811
Posted By vector
nevermind

nevermind
Forum: Miscellaneous Math 2007-11-30, 13:32
Replies: 5
Views: 1,811
Posted By vector
see:...

see: http://www.research.att.com/~njas/sequences/table?a=1358&fmt=5

The proof can be made deterministic by using theorem 3 from http://arxiv.org/PS_cache/math/pdf/0506/0506067v1.pdf
Using it the...
Forum: Math 2007-11-30, 13:18
Replies: 9
Views: 1,546
Posted By vector
"Hence ord(a)|ord(b) is a necessary and...

"Hence ord(a)|ord(b) is a necessary and sufficient condition that there is a k so that bk = a in a cyclic group."

So, in other words, if the order of the element is greater than the order of the...
Forum: Miscellaneous Math 2007-11-30, 11:38
Replies: 5
Views: 1,811
Posted By vector
Proof of Goldbach Conjecture

I think I proved the Goldbach conjecture, here is proof:

This conjecture states that every even number greater than 2 can be expressed as the sum of two primes.

This conjecture can be restated...
Forum: Math 2007-11-27, 18:01
Replies: 9
Views: 1,546
Posted By vector
checking cyclic group belongingness of an element

How do I check if some element was generated by some base. For example if the base is 2 and modulus is 7 the elements that are generated are {1,2,4} while elements that are not generated are...
Forum: Factoring 2007-11-21, 21:51
Replies: 2
Views: 1,163
Posted By vector
This program does not run under windows XP.

This program does not run under windows XP.
Forum: Miscellaneous Math 2007-11-20, 18:14
Replies: 3
Views: 1,411
Posted By vector
I never knew that a composite modulus does not...

I never knew that a composite modulus does not have any primitive roots. :blush:
Maybe this can be used to make a new deterministic primality test. (A prime is a provable prime if there is a...
Forum: Miscellaneous Math 2007-11-20, 03:14
Replies: 3
Views: 1,411
Posted By vector
Finding totient using discrete logarithm

I am posting this here because I think there might be a serious flaw with this technique. Given composite N, generator g, and prime q. find a generator g that is a primitive root to a composite N...
Forum: GMP-ECM 2007-11-16, 00:30
Replies: 8
Views: 1,935
Posted By vector
I factored 2^3000-1 and found a factor of 71...

I factored 2^3000-1 and found a factor of 71 digits (8877945148742945001146041439025147034098690503591013177336356694416517527310181938001) How can I check if this is a new factor? In 2^20000-1 I...
Forum: Math 2007-11-14, 16:07
Replies: 7
Views: 1,250
Posted By vector
I increased the yield by sieving through primes...

I increased the yield by sieving through primes of the form x^n+1. Their (p-1)/ord(base,p) is frequently equal to k*y^n.
Forum: Math 2007-11-13, 15:35
Replies: 7
Views: 1,250
Posted By vector
"For a given prime p, there are not very many...

"For a given prime p, there are not very many elements with small order;
almost all elements have large order. However, finding an element of
small order is easy IF one has the factorization of...
Forum: Math 2007-11-13, 12:48
Replies: 7
Views: 1,250
Posted By vector
yes, that's exactly what I am asking.

yes, that's exactly what I am asking.
Forum: Math 2007-11-13, 06:44
Replies: 7
Views: 1,250
Posted By vector
Smile efficient generation of highly non-primitive roots

Is there a way to systematically generate highly non-primitive roots. But that I mean keeping the base the same and modding it with a generated prime such that the resulting order of the base has a...
Showing results 1 to 25 of 25

 
All times are UTC. The time now is 21:51.


Tue Oct 19 21:51:24 UTC 2021 up 88 days, 16:20, 0 users, load averages: 1.51, 1.48, 1.46

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.