I_n is set of solutions x^2 −2xy+y^2−4^n = 0 , where y \in I_{n-1}
Source: ITAMO 1987 p4
February 2, 2020
equationSetsalgebra
Problem Statement
Given , define recurrently as the set of solutions of the equations ,
where ranges over all elements of . Determine the union of the sets over all nonnegative integers .