Putnam 2002 B5
Source:
March 12, 2012
Putnamcollege contests
Problem Statement
A palindrome in base is a positive integer whose base- digits read the same backwards and forwards; for example, is a -digit palindrome in base . Note that is not a palindrome in base , but it is a -digit palindrome: in base , and in base . Prove that there is an integer which is a -digit palindrome in base for at least different values of .