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Solver
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Apolyton Duke Of Something
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Latvia, Riga
Sep 2000
time: 07:30
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There's a problem in maths, IIRC, yet unsolved, but I don't remember the name. Tried Googling, but to no luck.
Here's the essence of it.
Take any number. If the number is odd, multiply it by three and add 1. If not odd, divide by 2. Do the same with the result. In the end, you'll always come to 4,2,1, which repeat forever. Like:
40. Not odd, divide by 2 =20. 20:2=10. 10:2=5. 5 odd, 5*3+1=16. 16:2=8 8:2=4 4:2=2 2:2=1 1*3+1=4
Obviously, 4,2,1 will repeat itself.
There were some good docs on this problem online, but please someone help me get the name of it!
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Ramo
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Austin, Texas, USA
Oct 1999
time: 23:30
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Is the word you're looking for "recursive?"
And what's unsolvable about it? Looks pretty straightforward.
1. If you have an odd number you can represent it as, where z is an integer, 2z + 1. So if you multiply by 3 and add one, you have 6z + 4, which is even and proceed to step two.
2. If you have an even number, you can represent it as 2z. So if you halve it, you have z. If z is even, you repeat step two. If it's odd, you can generate another even number by step one. Through this process, you'll eventually generate a number that's 2z*, where z* is a positive integer, which this algorithm reduces to 22, 21, 20.
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Eli
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Israel
Jul 2000
time: 07:30
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Nope, not M.
Collatz is the name.
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Ramo
how do you know you'll eventually reach a power of 2?
thats the key hole in you reasoning.
I seem to have read about this a year or so ago. Not sure its this exact one but sounded something like it and the exact proof was still not done at the time.
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panag
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MY WORDS ARE BACKED WITH BIO-CHEMICAL WEAPONS
Oct 2000
time: 07:30
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quote:
Originally posted by Solver
I know it's adding of one that produces an even number, didn't bother to write. Multiplication by 3 is, though, again, to get a big enough even number (when you add 1).
Panag, if I mail a uni, they're not gonna solve it all of a sudden if noone previously could  . |
hi ,
thats true , but héy , they might come up with a reason as to why , bla - bla , scientifical explanation , etc , ......
have a nice day
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05-08-2003 02:39
, Solver why dont you ask one of them internet math solution site's , ...... 
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