

1 + 2 + 3 + .. = -1/12 - aronvox
http://en.wikipedia.org/wiki/Ramanujan_summation

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michaelhoffman
The title is fairly misleading. The summation is not equal to -1/12, it is
-1/12(ℛ), where the (ℛ) indicates that the answer is actually infinite, but it
has a defined relationship to other series denoted in the same way.

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kabdib
Is the math here sloppy, or is it just me? Third equation they're bringing out
B(i) and K(whatever).

I made it through multivariable calculus and grads and so forth, but the
computer scientist in me gets upset when I run into undefined or poorly
specified notation.

"Oh," someone will reply, "You didn't know that B(i) is the Frogglegoop
function for ..." and I'll say, "Nope."

I rage quit denotational semantics after failing to find definitions of the
hieroglyphs in two different textbooks. If you're going to bring greek and
single letter function names to the game, you could at least provide a symbol
table, eh?

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zombie_hitler
You can't rearrange a divergent series. It's a sin :-P.
[http://www.math.ucla.edu/~ralston/pub/Rearrange.pdf](http://www.math.ucla.edu/~ralston/pub/Rearrange.pdf)

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Ellipsis753
I might have missed this but what use does this have? (Honest question.)

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fchollet
Ah, mathematics. Most of it is absolutely useless, and yet, Physics and
engineering won't stop finding new applications for the most abstract
mathematical concepts. Modern physics would have been impossible to develop
without the useless math concepts invented throughout the 19th century.

~~~
exDM69
> Modern physics would have been impossible to develop without the useless
> math concepts invented throughout the 19th century.

Case in point: imaginary numbers were "discovered" in the 16th century and
were widely considered to be "useless" by contemporary mathematicians and
scientists. However, in the 19th century it was realized that complex
arithmetic is perfect for analyzing steady state alternating current circuits.

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3327
[https://en.wikipedia.org/wiki/Monstrous_moonshine](https://en.wikipedia.org/wiki/Monstrous_moonshine)

