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A165071 a(n) = image of n under the base-7 Kaprekar map n -> (n with digits sorted into descending order) - (n with digits sorted into ascending order) 30

%I

%S 0,0,0,0,0,0,0,6,0,6,12,18,24,30,12,6,0,6,12,18,24,18,12,6,0,6,12,18,

%T 24,18,12,6,0,6,12,30,24,18,12,6,0,6,36,30,24,18,12,6,0,48,48,96,144,

%U 192,240,288,48,0,48,96,144,192,240,96,48,48,96,144,192,240,144,96,96,96

%N a(n) = image of n under the base-7 Kaprekar map n -> (n with digits sorted into descending order) - (n with digits sorted into ascending order)

%H Indranil Ghosh, <a href="/A165071/b165071.txt">Table of n, a(n) for n = 0..16807</a> (terms 0..2401 from Joseph Myers)

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

%e For n = 11, 11_10 = 14_7. So, a(11) = 41_7 - 14_7 = 29 - 11 = 18. - _Indranil Ghosh_, Feb 02 2017

%t a[n_] := With[{dd = IntegerDigits[n, 7]}, FromDigits[ReverseSort[dd], 7] - FromDigits[Sort[dd], 7]];

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

%Y Cf. A165072.

%Y In other bases: A164884 (base 2), A164993 (base 3), A165012 (base 4), A165032 (base 5), A165051 (base 6), A165090 (base 8), A165110 (base 9), A151949 (base 10).

%K base,nonn

%O 0,8

%A _Joseph Myers_, Sep 04 2009

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Last modified November 27 15:33 EST 2020. Contains 338683 sequences. (Running on oeis4.)