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May 5th, 2017, 02:17 AM  #11 
Math Team Joined: Jul 2011 From: North America, 42nd parallel Posts: 3,232 Thanks: 189 
That was an excellent explanation Mon Ami. I get it now. I broke out the French in gratitude Denis 
May 5th, 2017, 02:33 AM  #12 
Math Team Joined: Jul 2011 From: North America, 42nd parallel Posts: 3,232 Thanks: 189 
However ... $ 101 \ \ $ is the mirror of $ \ \ 101 \ \ $ but it is also the $ \ \ 25th \ \ $ prime. The mirror of $ \ \ 25 \ \ $ is $ \ \ 52 \ \ $ but the $ \ \ 52nd \ \ $ prime is not $ \ \ 101$ ??? 
May 5th, 2017, 03:47 AM  #13 
Global Moderator Joined: Dec 2006 Posts: 16,947 Thanks: 1255 
It wasn't asserted that 101 is interesting. I would guess that there are further interesting primes and that they are palindromic. After all, one can easily get "close": 191 is palindromic, but is the 43rd prime, where 43 isn't palindromic (but 44 is).

May 5th, 2017, 04:03 AM  #14 
Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 9,076 Thanks: 622 
101 is 26th prime; you're not including "2"? I don't know what is meant with these palindromes... That's why I skipped them. Perhaps the position number has to be also a palindrome: like, if 101 was 22nd prime. However, no such cases with 3digit primes. There are 15 of those critters: 101,131,151,181,191,313,353, 373,383,727,757,787,797,919,929 A plus tard Monsieur L'Agent! Note: sorry Skip, didn't see your post... Last edited by Denis; May 5th, 2017 at 04:19 AM. Reason: Add note 
May 5th, 2017, 12:07 PM  #15 
Math Team Joined: Jul 2011 From: North America, 42nd parallel Posts: 3,232 Thanks: 189  
May 5th, 2017, 12:22 PM  #16 
Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 9,076 Thanks: 622  

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