Re: Prime factorization

From: Wilhelm (willem_at_bermon-dot-net.no-spam.invalid)
Date: 09/27/04 

Date: 27 Sep 2004 10:32:02 -0500

> Phil Carmodywrote:
willem@bermon-dot-net.no-spam.invalid (Wilhelm) writes:
>
> Ok well thank you for the commenting i'll explain my method then.
>
> n!+a is always divisable by a if a<=n
>
> So if you take a factorial for example n! and take out all
divisables
> lower than n and higher than 1 then you can reuse it as an overlay
> (sieve) to either filter out new candidate divisables or generate a
> new sieve.
>
> So if we start of withe a sieve of 2! (P is possible prime and X is
> composite)
>
> 2! P,P
> 3! P,P,P,P,P,P removing divisables by 2 results in P,X,P,X,P,X
> 4! P,X,P,X,P,X,P,X,P,X,P,X,P,X,P,X,P,X,P,X,P,X,P,X removing
divisables
> by 3 results in P,X,X,X,P,X,P,X,X,X,P,X,P,X,X,X,P,X,P,X,X,X,P,X
>
> let's say i use the 4! sieve i can generate candidates as follows
>
What does 4! give you that 6 doesn't?
 
...
> The sieve will not find numbers <n but these can be found when
> creating the sieve. Anyway computations above 9! are memory hogs so
>
What does 9! give you that 210 doesn't?

You're reinventing the wheel.

Phil 

-- 
They no longer do my traditional winks tournament lunch - liver and
bacon. 
It's just what you need during a winks tournament lunchtime to replace
lost 
... liver.   -- Anthony Horton, 2004/08/27 at the Cambridge 'Long
Vac.'[/quote:6927d72186]
Well i certainly did not come here to get flamed or pushed into the
ground. So my idea isn't going to work on 100digit big primes but
it's doing quite nicely on big prime numbers and it does work nicely
as a prime number generator.
I merely came here to ASK if this was good or not, i didn't say it was
the holy grail of prime factorization nor did i ask to get blown out
of the water.
No i haven't read up much on factorizing numbers but i do know what
the problem involves. What's wrong with giving your own shot at the
problem, imo nothing.
 
Anyway i learn't today that this forum doesn't have very much nice
people like Phil with his fucked up comments, ever heard of
productive commentary?. I did get a few comments i can use thank you
to those people.
Also this forum keeps coming up with Error 500 which someone should
look at.
And for your information 9! = 362880 and i made a boo-boo because 10!
is doable which is approx 3628800*whateveryouusetostoreyournumbers 
of sieving data.
And yes this is reinventing the wheel.  What's wrong with that?
And also as i said this is the beginning and there's much to work on,
knowing i'm a long way off is a good thing. There are a number of
things i came up with that can reduce the problem making it slice
through many times faster.