The Collatz Conjecture in PostgreSQL | Hacker News Reader

The Collatz Conjecture in PostgreSQL

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CTE's are awesome indeed :)

As another interesting use case, here's the solution of the "eight queens problem" in Postgres:

https://gist.github.com/adewes/5e5397b693eb50e67f07

An here's the accompanying article:

http://andreas-dewes.de/articles/solving-the-eight-queens-pr...

(Better?) known also as the Syracuse problem: I had never heard about the "Collatz conjecture"; in French speaking countries, it's exclusively called the Syracuse problem.

I wonder how names for this conjecture have diverged like that...

Interesting! As an American I'd never heard that name for it. Usually it's called Collatz conjecture or the hailstone numbers in my experience.

All those names and more are included on the Wikipedia page it seems: https://en.wikipedia.org/wiki/Collatz_conjecture

The French Wikipedia page about it is actually https://fr.wikipedia.org/wiki/Conjecture_de_Syracuse !

Going through the Wikipedia articles in all the languages (I can read), the French one is the only one primarily naming it after Syracuse. Could that be the result of the contentious relationship between France and Germany, Collatz being a German mathematician?

According to the French Wikipedia article, in 1952, after a visit in Hamburg, Collatz explained the problem to Helmut Hasse, who brought the problem to the US in the university of Syracuse, hence the name "Syracuse problem".

So this name appears after the 2nd World War, at a time when the relations between France and Germany are becoming friendlier (https://en.wikipedia.org/wiki/France%E2%80%93Germany_relatio...).

I guess that French researchers heard about the problem from someone from the university of Syracuse.

Mathematicians seem to have settled on calling it the 3x+1 problem. I think this book is the edited by the current authority on the subject:

http://www.amazon.com/Ultimate-Challenge-3x-Problem/dp/08218...

https://en.wikipedia.org/wiki/Collatz_conjecture

This requires a GitHub account, and I have deleted my GitHub account after a GitHub VP said "The problem for diversity is the white women" (in a leaked presentation at the end of last year). https://www.reddit.com/r/pics/comments/44ttzj/racist_diversi...

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