Given that, a, b, and c are all positive integers so that a < b < c, and 1/a, 1/b, and 1/c are in arithmetic progression, can a² + b² be equal to c²?

(In reply to re(2): I think I have it by Mindrod)

http://mathworld.wolfram.com/ArithmeticProgression.htm does not say anything specific about what d is in its definition:

An arithmetic progression, also known as an arithmetic sequence, is a sequence of numbers {a_0+kd}_(k==0)^(n-1) such that the differences between successive terms is a constant d.

This is the online version of the reference you cite.

Edited on February 8, 2006, 5:32 pm

Posted by Richard on 2006-02-08 13:39:51