Great site for mathematical puzzles

Hello to all, I need your help!

No money involved just some of your braincells. Those involving memory.

Some year's ago, some of you fellows came up with a great link to a site collecting mathematical puzzles. Many had logins to the site and a sort of competition among us LG-addicts had begun to who would find the most answers.

I am sure ypercube was one of them and I think FatPhil also...

Can anyone remember the name? And the link?

Thanks in advance!

bennok

I wasn't on that group but I seem to recall one forum topic phrased exactly like this one, so it might be just a matter of finding it and then clicking on the link.

http://www.mathpuzzle.com/ ?

Of course, I googled a bit before posting, but found nothing :(

Are you talking about Project Euler?

http://projecteuler.net/

Currently 339 problems to solve at this site. Many are very difficult. Many require solving via writing a program of some kind.

That was the one, yup.

Argh. I've just gone back there and cracked out another dozen.

Some I've not addressed yet are low hanging fruit, but would require either more coding than runtime (too much effort for something simple), or way more runtime than coding (too simple a problem to be interesting if dumb brute force can crack it). Hopefully my temptation level won't reach too high a level...

Euler it is! I tried Newton and Leibniz but it felt wrong. Thanks a lot Ed!

My son has started coding pascal on an old PALM machine (you these great little PDAs from a distant time when the iPhone didn't exist) and I thought Project Euler would be a good source for finding interesting coding challenges.

If anyone is interested on how to use Pascal on a palm, it is achieved by an impressive french freeware, ppcompiler, which was recently ported to Android.

@Carroll: I managed to find one "Emmental" problem here.

The exact phrase was "a problem a day keeps the Emental away".

Don't blame ypercube for the missing "m", he lives much further from Emmental than I do!

What's the significance of Emmental?

Emmental is a small valley in Bern Switzerland where the variety of cheese that bears the same name is produced. Oh and "bears" are also a symbol for Bern but I am off topic: Bears eat cheese but they don't solve puzzles of any kind!

Yep, but Emental is the name for that mental illness that makes you forget things and names and correct spelling.

It's from a joke I heard some time ago:

Old lady in store: Give me 300 gr. of this yellow, ...er, yellow Alsheimer, young man.

Young man (employee): You mean this yellow cheese grandma?

Old lady: Yes, I have this Emental disease and I forget names sometimes.

So are people actually back active again on Project Euler?

I'm chuffed as I just pushed myself over the 100 limit (I had 74 before I resumed).

Caroll: do you have any hints on the sin/cos problem? I never did figure that one out...

Bears can solve puzzles such as "Where's the cheese?"

But there has been no documented case of a bear solving any of these.

On a related note, Alkulukuja Paskova Karhu

http://www.math.ust.hk/excalibur/v7_n1.pdf

Solution on page 3. I apparently misinterpreted the problem; you are supposed to find real solutions or prove that it has none, not find the complex solutions.