Continued fractions for (ir)rationals

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The discussion centers on the implications of continued fractions for the mathematical constants gamma (γ) and exp(γ). It references a paper that computes gamma to 30,100 decimal places and establishes that if γ or exp(γ) can be expressed as a fraction P/Q, then the denominator |Q| exceeds 10^15,000. The theorem presented indicates that both constants are highly unlikely to be rational, with |Q| being greater than 10^10,000. The foundational work cited is A. Ya. Khinchin's book "Continued Fractions," which provides essential insights into this topic.

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From http://web.comlab.ox.ac.uk/oucl/work/richard.brent/pub/pub049.html :

"Using one of the algorithms, which is based on an identity involving Bessel functions, gamma has been computed to 30,100 decimal places. By computing their regular continued fractions, we show that, if gamma or exp(gamma) is of the form P/Q for integers P and Q, then [itex]|Q|>10^{15000}[/itex]."

The method of getting to this result is not mentioned in this paper, but an earlier paper by one of its authors says this:

"Let [itex]x=\gamma\textrm{ or }\exp(\gamma)[/itex]. From Theorem 17 of [15], [itex]|Q_nx-P_n|\le|Qx-P|[/itex] for all integers P and Q with [itex]0<|Q|\le Q_n[/itex]. Using [itex]q_1,\ldots,q_{20000}[/itex], we find [itex]Q_{20000}(\gamma)=5.6\ldots\times10^{10328}[/itex] and [itex]Q_{20000}(\exp(\gamma)=3.3\ldots\times10^{10293}[/itex]. Hence, we have the following result, which makes it highly unlikely that [itex]x=\gamma\textrm{ or }\exp(\gamma)[/itex] is rational.
THEOREM. If [itex]x=\gamma\textrm{ or }\exp(\gamma)[/itex] = P/Q for integers P and Q, then [itex]|Q|>10^{10000}[/itex]."

The paper referenced is "A. Ya. KHINTCHINE (A. Ja. HINČIN), Continued Fractions, 3rd ed., (English transl. by P. Wynn), Noordhoff, Groningen, 1963. MR 28 #5038.". The author's name is now usually spelled Khinchin (of Khinchin's Constant fame).I'm trying to find that result (possibly even with a proof) which I take to be a basic result. Can anyone state it or give a common name for it?
 
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That's not a paper, its a book:

A. Ya. Khinchin, Continued Fractions, Dover reprint, 1997

You can purchase it for a five dollars American or something like that. I recommend that you do just that because its a beautiful book. Make sure to look for the wonderful connections with ergodic theory!
 
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