Find explicit function for recursively defined function
Source: Germany Bundeswettbewerb Mathematik 2001, Round 1, Problem 2
February 1, 2009
functionquadraticsalgebra unsolvedalgebra
Problem Statement
For a sequence we have a_0 \equal{} 1 and a_{n\plus{}1} \equal{} a_n \plus{} \sqrt{a_{n\plus{}1} \plus{} a_n} \forall n \in \mathbb{N}. Prove that this sequence is unique and find an explicit formula for this recursively defined sequence.