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Let the $\Omega$ constant be defined by the following integral:

$$\frac1{1+\Omega}=\int_\mathbb R\frac{\mathrm dt}{(e^t-t)^2+\pi^2}$$

How does one go about showing that $\Omega$ is the real solution to

$$1=\Omega e^\Omega$$

I tried starting by considering a semicircle contour and taking residues,

$$e^z-z=\pi i\\\implies z=-W_k(1)-\pi i$$

This has imaginary part greater than $0$ when $k\ge1$ where $W_k(z)$ is the Lambert W function, hence,

$$\int_\mathbb R\frac{\mathrm dt}{(e^t-t)^2+\pi^2}=2\pi i\sum_{k\ge1}\operatorname{Res}\limits\limits_{z=-W_k(1)-\pi i}\left(\frac1{(e^z-z)^2+\pi^2}\right)$$

But I haven't the slightest clue how I would go from here.

Any simpler ideas?

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