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PRIME NUMBERS
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You are currently reading a thread in /sci/ - Science & Math

for prime number-fags: I'm trying, just for fun, to figure out how to prove the following property of prime numbers: given three consecutive prime numbers x, y, z, the bigger they are the more their sum x\y + y\z + z\x tends to be 6. any suggestion?
>>
its actually 3, not 6
prove it for consecutive integers first, then look up the properties of primes on wikipedia and see that the proof for primes is just as trivial
>>
>>7766655
It is very easy to prove it false. Take three random consecutive primes and test those ratios. They will be very far away from six.

Then take another three bigger consecutive primes. They will be even more far away from six. Theorem discarded.
>>
if

x < y < z

then in

x\y + y\z + z\x

the first two are smaller than 1 and the last is quite big.

I don't see how this would converge to something small.
>>
>>7766663
Pretty sure this is correct

let x<y<z

(I think) You can use the prime number theorem's estimate of ln(x) for prime gaps as you go to infinity,

x/y -> x/(x+lnx) -> 1
y/z -> y/(y+lny) -> 1
z/x -> (y+lny)/x = (x+lnx+ln(x+lnx))/x -> 1
>>
>>7766671
The prime numbers are quite common :-).

If I remember correctly about (n / ln n) in 1..n (n -> inf).

So three consecutive primes will be really close (relatively). As they get bigger the sum will get closer and closer to 3.
>>
>>7766655
http://www.wolframalpha.com/input/?i=lim+x+to+infty+x%2F%28x%2Ba%29%2B%28x%2Ba%29%2F%28x%2Bb%29%2B%28x%2Bb%29%2Fx
>>
>>7766744
does have nothing to do with primes, itsa true for all natural numbers:
y=x+a
z=x+b

lim x to infty (x/(x+a)+(x+a)/(x+b)+(x+b)/x) = 3
>>
>>7766699
I don't get it, but it's pretty interesting. Can you address me to a link \ paper where it's proved more in detail?
>>
>>7766655
Uhhhhhh
This works for any number.
When the numbers are EXTREMELY HUGE and close together, they're essentially the same number, very small difference.
And dividing a number by something that is basically the same number, you get 1
So its literally just 1+1+1=3
OP, you are a brainlet if this was surprising to you.
>>
>>7766744
>>7766749
If a, b is a fixed number, then this is clear.
The question is how the growth of the distance with x is.

anyway, if
>>7766699
has the statistics right,
z/x = (x+b(x)) / x
indeed goes to 1.
>>
>>7766757
https://en.wikipedia.org/wiki/Prime_number_theorem