

What is the probability that gcd(n,m)=1?  - hhm
http://primes.utm.edu/notes/relprime.html

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andrewf
Handy take on this: <http://ridiculousfish.com/blog/?p=23>

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michael_dorfman
That was very cool-- a CAPTCHA that uses number theory to calculate Pi as a
side effect.....

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henning
One of the oddest things about math, to most people, is how a constant like
pi, from geometry, appears in all kinds of things that have little or nothing
to do with circles.

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dfranke
I still remember having to figure this out for a takehome exam in number
theory.

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time_management
This is a poorly-formed question, because there's no such thing as a uniform
randomly-chosen integer. It's more accurate to say that the probability of
gcd(m, n) = 1, with m and n chosen from {1, ..., N}, approaches 6/pi^2 as N ->
infinity.

