There are no Diophantine quadruples of Fibonacci numbers
Tom 185 / 2018
                    
                    
                        Acta Arithmetica 185 (2018), 19-38                    
                                        
                        MSC: Primary 11D09; Secondary 11B39.                    
                                        
                        DOI: 10.4064/aa170613-8-12                    
                                            
                            Opublikowany online: 18 June 2018                        
                                    
                                                Streszczenie
We show that there is no Diophantine quadruple, that is, a set $\{a_1,a_2,a_3,a_4\}$ of four positive integers such that $a_ia_j+1$ is a square for all $1\le i \lt j\le 4$, consisting of Fibonacci numbers.