Consider the numerical pyramid below, formed by simply putting down the series of odd numbers into a pyramid.
7 9 11
13 15 17 19
. . .
Find a formula for the sum of the numbers in the nth row, and prove it.
(In reply to solution
Don't we need to prove that the first element in each row is indeed n² - n + 1?
Posted by Charlie
on 2003-10-14 14:17:41