Henry Ernest Dudeney/Puzzles and Curious Problems/229 - Geometrical Progression/Solution

by : $229$

 * Geometrical Progression

Solution

 * $121 = 3^0 + 3^1 + 3^2 + 3^3 + 3^4 = 11^2$


 * $400 = 7^0 + 7^1 + 7^2 + 7^3 = 20^2$

Proof
This is explored in Square Numbers which are Sum of Consecutive Powers.