MathDB
n = a*b , numbers of the form a^b

Source: Azerbaijan NMO 2023. Senior P1

August 24, 2023
number theoryAZE SENIOR NATIONAL MO

Problem Statement

The teacher calculates and writes on the board all the numbers aba^b that satisfy the condition n=a×bn = a\times b for the natural number n.n. Here aa and bb are natural numbers. Is there a natural number nn such that each of the numbers 0,1,2,3,4,5,6,7,8,90, 1, 2, 3, 4, 5, 6, 7, 8, 9 is the last digit of one of the numbers written by the teacher on the board? Justify your opinion.