We shall call an integer n cute if it can be written in the form $n = a^2 + b^3 + c^3 + d^5$, where $a, b, c$ and $d$ are integers. a) Determine if the number $2020$ is cute. b) Find all cute integers
Problem
Source: 2020 Grand Duchy of Lithuania, Mathematical Contest p4 (Baltic Way TST)
Tags: number theory