M Cipu,
A Dujella, Y Fujita - Mediterranean journal of mathematics, 2022 - Springer
In this paper, we prove that if {a 1, b, c, d} and {a 2, b, c, d} are Diophantine quadruples with
a 1< a 2< b< c< d, then a 2> 24 3, a 2> max {36 a 1 3, 300 a 1 2}, b< a 2 3/2, and 16 a 1 2 b …