# Determining prime numbers

Discussion in 'OT Technology' started by [DWI], Sep 30, 2003.

1. ### [DWI]Master of Nothing

Joined:
Aug 6, 2000
Messages:
21,936
0
Location:
Maine
What's the easiest way to do this?

2. ### 5Gen_PreludeThere might not be an "I" in the word "Team", but

Joined:
Mar 14, 2000
Messages:
14,520
2
Location:
I've tried drawing them out of a hat but the odds decrease as the numbers go higher. Then I tried sitting a monkey down to a typewriter - sure I got one of them to write "In the beginning" but I mean that didn't help at all with my prime project. Then I went to the hardware store and asked for some prime numbers and the guy just gave a bunch of digits that were primed ready for paint. I asked my butcher about it but all he wanted to sell me was prime rib. While I was in the mall, I wandered over to the bank and they said they give me half a percent over prime and I figured I was finally on to something but I ended up with a lot of paperwork to fill out. Finally I ended up writing to leader of my country but well, he's retiring in February so I just gave up.

Joined:
Oct 21, 2001
Messages:
245,192
0
use a lookup table - determining prime number takes a lot of work once you get above trivial numbers

4. ### RickNew Member

Joined:
Feb 20, 2002
Messages:
1,735
0
Location:
Henderson, NV

5. ### Penguin ManProtect Your Digital Liberties

Joined:
Apr 27, 2002
Messages:
21,696
0
Location:
Edmonton, AB
I have an algorithm for it here somewhere... Something to do with square roots and six or something like that, maybe I'll try to find it later. Hey, this could be an article in the possible newsletter

6. ### CyberBulletsI reach to the sky, and call out your name. If I c

Joined:
Nov 13, 2001
Messages:
11,865
0
Location:
or a project to find the most efficent way to figure out prime numbers

7. ### Joe_CoolModerator

Joined:
Jun 30, 2003
Messages:
301,276
1,225
Well, all primes > 3 have to be of the form 6n+1 or 6n-1. But unfortunately there's no good way to generate all of them reliably except checking all possible divisors.

8. ### 5Gen_PreludeThere might not be an "I" in the word "Team", but

Joined:
Mar 14, 2000
Messages:
14,520
2
Location:
Well that's where it comes in handy to keep track of the ones you've already found . LCD's are all primes remember.

Joined:
Jun 28, 2002
Messages:
39,835