Add new comment

I can't help you with any literature, but I was intrigued by your observation that the repeated subtraction of a number from the absolute value of its reverse produced a palindrome.

I wrote a computer program to explore this and found that all numbers up to 10,002 become palindromes. The first number that doesn't result in a palindrome is 10,003. By not producing a palindrome I mean that doesn't produce one by the time the difference reaches a certain value, 9,223,372,036,854,775,807 in my case.

The program calculated

difference = number - absolute value(reverse)

using the difference as the new number.

The program repeated the calculation until the difference either became a palindrome or reached 9,223,372,036,854,775,807. A palindrome might result if this number were larger, but it might not. It's very much like Lychrel numbers in that regard.

Filtered HTML

  • Web page addresses and email addresses turn into links automatically.
  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.