Prove that if A = ½(15+√197), then 7 is a factor of [A^n] for all positive integer values of n, where [w] denotes the greatest integer less than or equal to w.
You're on the right track Ady, but need to show that the SUM A^n + B^n = 7k+1 where k is a positive integer.

Posted by Dennis
on 20070226 12:14:00 