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Numerical Palindromes

  1. Oct 29, 2009 #1
    not really math but wondering if someone is clever enough to know answer to this..

    Some of you may know that if you pick (almost) any integer and add its reversed digits to it, and repeat this process ..you will eventually get a palindrome.

    for example:
    # 56 becomes palindromic after one iteration: 56+65 = 121.
    # 57 becomes palindromic after two iterations: 57+75 = 132, 132+231 = 363.
    # 10,911 reaches the palindrome 4668731596684224866951378664 after 55 steps

    If we call the numbers we start with as "seeds" ...we can easily produce a palindrome given (almost) any seed.

    How do we extract a seed from a given palindrome?
    (note that all intermediate steps count as seeds..so you only need to go back "1 step")

    any ideas?
  2. jcsd
  3. Oct 29, 2009 #2


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    Actually, I would expect the opposite: that almost all numbers are 'Lychrel' numbers. I think looking at 1-10 digit numbers gives us a bad feeling for their asymptotic behavior, since ,ost numbers are large.
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