How many numbers, from 1 to 50 (both included) can you arrange in a row (one of each) so that each one, except the first and the last, is the sum or difference of its two neighbours?

Example: 3, 10, 7, 17, 24, 41.

10 = 3+7, 7 = 17-10, 17 = 24-7, 24 = 41-17.

Nine I see:  1 3 2 5 7 12 19 31  50

Tenish, anyone??

 

Posted by Ady TZIDON on 2008-11-20 11:38:46