MathDB
a_n + a_{n + 1} always a perfect square

Source: 2019 Swedish Mathematical Competition p6

May 1, 2021
SequencePerfect Squarenumber theory

Problem Statement

Is there an infinite sequence of positive integers {an}n=1∞\{a_n\}_{n = 1}^{\infty} which contains each positive integer exactly once and is such that the number an+an+1a_n + a_{n + 1} is a perfect square for each nn?
Back to ProblemsView on AoPS