MathDB
x_(n+2) = 2^(-x_n) + 0.5

Source: Vietnam MO 2008, Problem 4

August 26, 2008
limitalgebra unsolvedalgebra

Problem Statement

he sequence of real number (xn) (x_n) is defined by x_1 \equal{} 0, x_2 \equal{} 2 and x_{n\plus{}2} \equal{} 2^{\minus{}x_n} \plus{} \frac{1}{2} \forall n \equal{} 1,2,3 \ldots Prove that the sequence has a limit as n n approaches \plus{}\infty. Determine the limit.