Spreadsheets lend themselves naturally to recursive computations, since a formula can be defined as a function of one of more preceding cells. A hypothesized closed form for the "n"th term of a recursive sequence can be tested easily by using a spreadsheet to compute a large number of the terms. Similarly, a conjecture about the limit of a series can be tested by using a spreadsheet to compute a number of partial sums recursively. Once students are confident that a closed form is probably not wrong, they can prove it correct by mathematical induction. (Contains 5 tables.)