BrainDen.com - Brain Teasers
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## Question

My 1000th post.

Maybe I should give my keyboard a rest.

Anyway Happy Easter, and here's a little gem for you.

Take a number N, reverse its digits and add it to N.

Repeat if necessary. Eventually you will get a palindrome.

For example, starting with 39, we have 39 + 93 = 132.

Then 132 + 231 = 363 = palindrome.

After a moment's thought, this is not surprising.

But sometimes you do have to be patient.

Consider the starting number 89:

```					  89	  ------>   159487405
187	 |		  664272356
968	 |		 1317544822
1837	 |		 3602001953
9218	 |		 7193004016
17347	 |		13297007933
91718	 |		47267087164
173437	 |		93445163438
907808	 |	   176881317877
1716517	 |	   955594506548
8872688	 |	  1801200002107
17735476	 |	  8813200023188  =  palindrome!
85189247 --->[/code]```

## 27 answers to this question

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1. send me the file and I will upload it if it's ok

you mean via email? What email address should I send it to?

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bona and unreality - I don't know if you've seen this yet but it looks like we've just stumbled upon the tip of the iceberg. This guy has been running computer programs for over a decade to compute the largest iterations of palindromic numbers.

I was going to sit down and ponder a proof, but that site really discouraged me. Perhaps it is a good thing. I should probably spend that amount of time on something else. Loved this topic, though!

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