How many actually understand the "theory"

[gopher_yarrowzoo]

I was looking at exactly what I was "crunching" and well erm looking and going erm 'um and wtf... I do understand bits but I just glad I don't need to manually check anything can you imagine that..
So how many acually FULLY understand this then?
Discuss....

[LAURENU2]

Not me :hiya: I am to slow :bonk:

[jasong]

Not me :hiya: I am to slow :bonk:
Just for the heck of it, I tried 2^7-1 by hand. It's a similar theory, but I'm not sure how the k enters the picture.(In the case of GIMPS, k=1)

[PY 222]

Aren't we looking for prime numbers? :jester: :looney:

[CaptainMooseInc]

Yes we are looking for prime numbers but it's certain prime numbers to that fit within the specfied theory (equation). I don't understand it hardly at all (I can grasp the idea). I just wanna find the 17 primes as fast as possible so that way everyone can shift focus from SoB to RieselSieve.

[Marky-UK]

I don't do SoB but I think I understand the theory, and it's similar to Riesel Sieve too. I don't quite get all the neat ways of finding factors though.

Assuming I've got this right...

SoB and RS are both trying to find the smallest value of k for which k * (2^n) +/- 1 is not prime for all values of n greater than 1. Or rather trying to prove that the conjectured values (k=78,557 for SoB, k=509,203 for RS) are indeed the smallest.

You could pick a value of k, then work out every number from n = 1 upwards and see if it's prime - if it is, you can eliminate that value of k and move on to the next one.

For SoB, there's only 8 values of k left to eliminate. For RS, there's 69 I think.

For SoB (k*2^n+1), small values of k give you the numbers:

k=1 n=1 gives 3 which is prime
k=2 n=1 gives 5 which is prime
...
k=4 n=1 gives 9 which is not prime, then n=2 gives 17 which is prime
k=5 n=1 gives 11 (prime)
...
k=12 n=1 gives 25, n=2 gives 49, n=3 gives 97 (prime)

And so on. The first few values of k are easy to rule out with Excel - and it made me understand the theory a lot better.

[Helix_Von_Smelix]

Aren't we looking for prime numbers? :jester: :looney:

No!! it to do with the weather!!:thumbs: :banana:

Sunshine on beach 17 days in a row.

It's to do with Probabilities :cheers: :lmao: