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![[parent]](http://images.planetmath.org:8080/images/uparrow.png) Viewing Message
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| ``Re: Exciting Problem''
by dh2718 on 2008-07-09 03:39:02 |
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| Parashar's puzzle at http://projecteuler.net/index.php?section=problems&id=202
The correct answer is: 1209002624. This is lynx answer +/- 1, so that his argumentation is correct, up to computational errors. I got this number by brute force computation through a C program, my machine allowing 64-bits arithmetic. I didn't even bother to compute first the prime factors, as lynx did; doing so would have greatly reduced the computation time from 40 minutes (!) to probably a few minutes.
I also checked that my program gives the correct answer (80840) for 1000001, as it does for small numbers 5, 7, 9, 11... By the way, there is no path for a number of reflections which is a multiple of 3.
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