Let [z] mean the Greatest Integer less than or equal to z. Find a positive real number X, such that [X^n] is an even number whenever n is even, and [X^n] is an odd number whenever n is odd.
(In reply to
Solution without full spoiler by SteveH)
Ha, ha! I feel like an idiot! Shin's proof outline works! (5+sqrt(33))/2 should also have the desired property. Let r and s be the roots of x^2-3x-2. Then all terms r^n+s^n are ODD, for n>0. Bravo, David! And kudos, SteveH, for a marvelous problem!
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Posted by McWorter
on 2005-03-10 05:21:55 |