Date: Aug 15, 2007 11:23 PM Author: Randy Poe Subject: Re: Largest primeproduct with 2 as factor? On Aug 15, 7:00 pm, jonas.thornv...@hotmail.com wrote:

> On 16 Aug, 00:42, Randy Poe <poespam-t...@yahoo.com> wrote:

>

>

>

> > On Aug 15, 6:36 pm, jonas.thornv...@hotmail.com wrote:

>

> > > On 16 Aug, 00:18, stephane.fr...@gmail.com wrote:

>

> > > > On Aug 15, 3:03 pm, jonas.thornv...@hotmail.com wrote:

>

> > > > > On 16 Aug, 00:00, stephane.fr...@gmail.com wrote:

>

> > > > > > On Aug 15, 2:53 pm, jonas.thornv...@hotmail.com wrote:

>

> > > > > > > I do not know much math, i just wonder if there is a largest

> > > > > > > primeproduct with two as one of the factors.

> > > > > > > Same i wonder for three.

>

> > > > > > > If not..., but if so is it true for any primefactor used in

> > > > > > > primeproduct that they will have a range?

> > > > > > > Do every factor have a range in primeproducts?

>

> > > > > > > A pure guess tell me that the numbers of primeproducts with 2 or 3

> > > > > > > used as one of the factor is infinite but i am not sure.

>

> > > > > > > JT

>

> > > > > > You guess is right. This is because there is infinity prime number

> > > > > > then if N is the bigger prime product, you will find A your biggest

> > > > > > prime with A = N/2. You can find a prime number A' with A'> A, then N'

> > > > > > = A x 2 > N. Same rules with 3 or any prime numbers.

>

> > > > > > SF

>

> > > > > Could anyone tell me the biggest "known" primeproduct that has two as

> > > > > factor?- Hide quoted text -

>

> > > > > - Show quoted text -

>

> > > > Well dude , you can suppose you got one and then prove that you can a

> > > > bigger one .- D?lj citerad text -

>

> > > > - Visa citerad text -

>

> > > Ok an easy question i do not have any primeproduct algorithm going, so

> > > i would be interested in a list of primeproducts less than a million

> > > that has two as factor?

>

> > > Can not be that many or?

>

> > > If not that many would be nice for 10 000 000 and for 100 000 000?

>

> > > Well if already a million would have couple of 100 i am not that

> > > interested in the bigger numbers.

>

> > What do you mean by "primeproduct"? Do you mean any

> > number that has 2 as a factor?

>

> > For instance, does 2^20 = 1048576 qualify as a "primeproduct"?

>

> > If you just mean any number that has two as a factor,

> > these are called "even numbers", and any number that

> > ends in 0, 2, 4, 6, or 8 is such a number. Thus, here

> > is a large even number: 7924720394820394812476

>

> Sorry i am tired, it is of course

> 6=2*3,10=2*5,14=2*7,22=2*11,26=2*13,34=2*17,38=2*19 and so son.

> and for three

> 6=3*2,15=3*5,21=3*7,33=3*11,39=3*13....

>

> So forget my question

>

Ah. Well, these days primes far > 10^6 are easily

turned out in milliseconds by computer software.

You might be interested in this page:

http://primes.utm.edu/nthprime/index.php#nth

Not exactly what you're looking for, but if you

try various values of n you'll find a prime of the

size you want. Then obviously just multiply by 2.

For instance, the billionth prime is:

22,801,763,489

- Randy