Lychrel number

Unsolved problem in mathematics:
Do any base-10 Lychrel numbers exist?

A Lychrel number is a natural number that cannot form a palindrome through the iterative process of repeatedly reversing its digits and adding the resulting numbers. This process is sometimes called the 196-algorithm, after the most famous number associated with the process. In base ten, no Lychrel numbers have been yet proven to exist, but many, including 196, are suspected on heuristic[1] and statistical grounds. The name "Lychrel" was coined by Wade Van Landingham as a rough anagram of "Cheryl", his girlfriend's first name.[2]

  1. ^ O'Bryant, Kevin (26 December 2012). "Reply to Status of the 196 conjecture?". MathOverflow.
  2. ^ "FAQ". Archived from the original on 2006-12-01.