Putnam 2002 B5
- Session B
A palindrome in base is a positive integer whose base- digits read the same backwards and forwards; for example, is a 4-digit palindrome in base 10. Note that 200 is not a palindrome in base 10, but it is the 3-digit palindrome 242 in base 9, and 404 in base 7. Prove that there is an integer which is a 3-digit palindrome in base for at least 2002 different values of .
Curated text Kedlaya Putnam archive. Quoted with source.
Solutions
Human solution Solution 1 by Kiran Kedlaya and Lenny Ng
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