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a(n) = image of n under the base-3 Kaprekar map n -> (n with digits sorted into descending order) - (n with digits sorted into ascending order)
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%I #13 Jan 08 2020 09:42:57

%S 0,0,0,2,0,2,4,2,0,8,8,16,8,0,8,16,8,8,16,16,16,16,8,8,16,8,0,26,32,

%T 58,32,26,52,58,52,58,32,26,52,26,0,26,52,26,32,58,52,58,52,26,32,58,

%U 32,26,52,58,64,58,52,58,64,58,52,58,52,58,52,26,32,58,32,26,64,58,52,58,32

%N a(n) = image of n under the base-3 Kaprekar map n -> (n with digits sorted into descending order) - (n with digits sorted into ascending order)

%H Indranil Ghosh, <a href="/A164993/b164993.txt">Table of n, a(n) for n = 0..19683</a> (terms 0..2187 from Joseph Myers)

%H <a href="/index/K#Kaprekar_map">Index entries for the Kaprekar map</a>

%e For n = 10, 10_10 = 101_3. So, a(10) = 110_3 - 11_3 = 12 - 4 = 8. - _Indranil Ghosh_, Feb 02 2017

%t a[n_] := With[{dd = IntegerDigits[n, 3]}, FromDigits[ReverseSort[dd], 3] - FromDigits[Sort[dd], 3]];

%t a /@ Range[0, 100] (* _Jean-François Alcover_, Jan 08 2020 *)

%Y Cf. A164994.

%Y In other bases: A164884 (base 2), A165012 (base 4), A165032 (base 5), A165051 (base 6), A165071 (base 7), A165090 (base 8), A165110 (base 9), A151949 (base 10).

%K base,nonn

%O 0,4

%A _Joseph Myers_, Sep 04 2009