Over 2000 numbers are around a circle. Each number is the sum of its left and right neighbors.

Given that one of the numbers is a one, how many numbers (as a minimum) must there be?

(In reply to re(6): What now ? - you're right again !! by pcbouhid)

Even the obvious has a proof.  Charlie has eliminated 2-cycles and 3-cycles.  What if someone asks why not 1-cycles, or, why cycle at all?

(to pcbouhid:  Claudio participates in a portugese math e-list.  I met him the same way I met you all, on the internet, through our common interest in math.)

Posted by McWorter on 2005-06-01 21:57:52