2023-digit palindromes - Puerto Rico TST 2023.1.1
Source:
March 23, 2024
number theory
Problem Statement
A number is capicua if it is read equally from left to right as it is from right to the left. For example, and are capicua numbers.
(a) How many -digit capicua numbers can be formed if you want them to have at least equal digits?
(b) How many -digit capicua numbers can be formed if you want them to have at least equal digits?