{75, 100, 125} is an example of an arithmetic progression of positive integers such that the n-th term is a perfect n-th power.
Find a longer sequence with this feature.

What is the longest you can get?
P.S. Trival solution(d=0) excluded.

There are many solutions that I've found for a sequence of length 4, but my favorite one so far is:

213, 169, 125, 81 ... with a common difference of 44

Posted by Justin on 2010-07-22 15:34:44