General Continued Fractions and Irrationality
A while back I came across a result about non-simple continued fractions that allows proving that some numbers are irrational. The result in modern terminology is:
If, in the continued fraction $$\cfrac{b_1}{a_1 + \cfrac{b_2}{a_2 + \cfrac{b_3}{a_3 + \dots}}}$$ the values $a_{i}, b_{i}$ are all positive integers, and if we have $a_i \geq b_i$ for all $i$ greater than some $n$, then the value of the continued fraction is irrational.
I have checked that this result (which has been known for well over a century) can be used to prove the irrationality of $\pi$ and (non-zero) rational powers of $e$ (see here).
My question is this:
Does anyone know of any other uses of this old theorem for proving other constants are irrational? I am not naive enough to believe that mathematicians might have overlooked a neat proof of the irrationality of Euler's $\gamma$ or $\zeta(2n+1)$, but have searched in vain for any other uses, and not been able to find any by my own investigations.
Solution 1:
This is not an answer, just a comment from A few remarks on ζ(3) - Yu. V. Nesterenko