The general form of a geometric sequence is

is the first term, and

is the factor between the terms (called the “common ratio”)

Find a geometric series of **3** or more positive integers, starting with **1**,

such that its sum is a perfect square

that is,

For example,

Can you find other examples?

Advertisements

I can’t find anything else with a^2 <= 331 digit length squares equivalent to r = 2000 and n = 100.

Paul.

I couldn’t find anything else. It’s hard to prove it!