Search: id:A161732
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%I A161732
%S A161732 4,6,8,9,22,33,44,55,66,77,88,99,121,202,242,252,262,303,343,363,393,
%T A161732 404,484,505,525,606,616,626,686,707,808,909,939,1111,1331,1441,1661,
%U A161732 1991,2112,2222,2662,2772,2882,3333,3443,3773,3883,3993,4224,4444,5445
%N A161732 Fixed points of the TITO operation (A161594) that are also composite 
               palindromes.
%C A161732 This sequence is a proper superset of A046351 (palindromic composite 
               numbers with only palindromic prime factors). The smallest number 
               that doesn't belong to A046351 is 72927. The numbers that are in 
               this sequence and are not in A046351 are given in A161730.
%H A161732 T. Khovanova, <a href="http://blog.tanyakhovanova.com/?p=144">Turning 
               Numbers Inside Out</a> [From Tanya Khovanova (tanyakh(AT)yahoo.com), 
               Jul 07 2009]
%t A161732 reversepower[{n_, k_}] := FromDigits[Reverse[IntegerDigits[n]]]^k f[n_] 
               := FromDigits[ Reverse[IntegerDigits[Times @@ Map[reversepower, FactorInteger[n]]]]] 
               rev[n_] := FromDigits[Reverse[IntegerDigits[n]]] Select[Range[10000], 
               f[ # ] == # && rev[ # ] == # && ! PrimeQ[ # ] &]
%Y A161732 Cf. A161594, A161597, A161598, A161600, A046351
%Y A161732 Sequence in context: A032350 A078337 A046351 this_sequence A066307 A158340 
               A099071
%Y A161732 Adjacent sequences: A161729 A161730 A161731 this_sequence A161733 A161734 
               A161735
%K A161732 base,nonn
%O A161732 1,1
%A A161732 Tanya Khovanova (tanyakh(AT)yahoo.com), Jun 17 2009
%E A161732 Edited by N. J. A. Sloane, Jun 23 2009

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