|A simple puzzle (no prize offered :-)|
Message #1 Posted by Gerson W. Barbosa on 7 Jan 2008, 7:46 p.m.
Replace every # in the expression below with the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 (used only once). If you find the correct order you'll obtain .577215664901, that is, the first 12 digits in the Euler-Mascheroni constant. The algebraic object should evaluate correctly on the HP-28/48/49/50, but you can use whatever calculator you like. Actually the approximation yields the constant in excess of about 2E-14, but due to rounding errors the result is not rounded up properly.
I looked for some approximations at MathWorld
but none would fit my purpose, so I created this one. It took me about two or three hours playing on the HP-32Sii and half an hour on the HP-200LX to find the expression, which makes me think the puzzle can be solved in less time just using a trial and error method. If you don't have this much time to waste, writing a short program might be a better solution.
P.S.: The final expression was found on 1/7/8, 06:59:23.4p.m. (local time). (if not true, a close approximation ;-)