1. The problem statement, all variables and given/known data Hi, I'm having trouble on a question from Spivak's Calculus 4E. It's on page 27, chapter 2 and question number 2. He asks to find the formula for n Sigma i=1 (2i -1)= 1 + 3 + 5 + .... + (2n-1) 2. Relevant equations Unfortunately I don't know how to use the symbols on a thread like this; anyone care to assist? :) 3. The attempt at a solution Well since this is an induction chapter, I tried coming up with a formula using n+1 but that got me into a mess.