[MO] Residue at ∞ and ∑(-1)^n x^(2^(2^n))
#8
Hmmmmm.


Now I'm confused. I think you may be missing some background knowledge on complex analysis.

\[
\int_{|z| = 1} e^{1/z}\,dz = 2\pi i\\
\]

If I take \(k>1\):

\[
\int_{|z| = 1} e^{1/z^k}\,dz = 0\\
\]


This is not numerically verifiable; but it's mathematically true. Additionally we can substitute \(\xi = 1/z\); and take taylor coefficients at \(\xi\); which relate directly to the above values; but as "residue at infinity" relates to "residue at zero".


When we introduce:

\[
\int_{|z| = 1} e^{1/\sqrt{z}}\,dz\\
\]

It is impossible to take this integral without considering it in an "improper manner". Which was my point.


I apologize if I'm not making any sense. But from that point; could you perhaps elaborate further from this perspective? I'm not trying to be a jack ass, I'd just love to get a better grasp of what you mean???

Again, sorry.

James
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RE: [MO] Residue at ∞ and ∑(-1)^n x^(2^(2^n)) - by JmsNxn - 04/02/2023, 05:31 AM



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