
The Collatz Conjecture in PostgreSQL - ktamura
https://gist.github.com/kiyoto/4dbe676711e8e91659b02d72eced5446
======
ThePhysicist
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](https://gist.github.com/adewes/5e5397b693eb50e67f07)

An here's the accompanying article:

[http://andreas-dewes.de/articles/solving-the-eight-queens-
pr...](http://andreas-dewes.de/articles/solving-the-eight-queens-problem-in-
sql.html)

------
programLyrique
(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...

~~~
curiousGambler
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](https://en.wikipedia.org/wiki/Collatz_conjecture)

~~~
programLyrique
The French Wikipedia page about it is actually
[https://fr.wikipedia.org/wiki/Conjecture_de_Syracuse](https://fr.wikipedia.org/wiki/Conjecture_de_Syracuse)
!

~~~
danbruc
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?

~~~
programLyrique
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...](https://en.wikipedia.org/wiki/France%E2%80%93Germany_relations#France.2C_Germany.2C_and_United_Europe)).

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

------
pella
[https://en.wikipedia.org/wiki/Collatz_conjecture](https://en.wikipedia.org/wiki/Collatz_conjecture)

------
tajen
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...](https://www.reddit.com/r/pics/comments/44ttzj/racist_diversity_training_at_github/)

