A165110 a(n) = image of n under the base-9 Kaprekar map n -> (n with digits sorted into descending order) - (n with digits sorted into ascending order)

0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 0, 8, 16, 24, 32, 40, 48, 56, 16, 8, 0, 8, 16, 24, 32, 40, 48, 24, 16, 8, 0, 8, 16, 24, 32, 40, 32, 24, 16, 8, 0, 8, 16, 24, 32, 40, 32, 24, 16, 8, 0, 8, 16, 24, 48, 40, 32, 24, 16, 8, 0, 8, 16, 56, 48, 40, 32, 24, 16, 8, 0, 8, 64, 56, 48, 40, 32, 24, 16, 8

Offset

0,10

Links

Indranil Ghosh, Table of n, a(n) for n = 0..59049 (terms 0..6561 from Joseph Myers)

Index entries for the Kaprekar map

Example

For n = 11, 11_10 = 12_9. So, a(11) = 21_9 - 12_9 = 19 - 11 = 8. - Indranil Ghosh, Feb 02 2017

Mathematica

a[n_] := With[{dd = IntegerDigits[n, 9]}, FromDigits[ReverseSort[dd], 9] - FromDigits[Sort[dd], 9]];
a /@ Range[0, 100] (* Jean-François Alcover, Jan 08 2020 *)

Crossrefs

Cf. A165111.

In other bases: A164884 (base 2), A164993 (base 3), A165012 (base 4), A165032 (base 5), A165051 (base 6), A165071 (base 7), A165090 (base 8), A151949 (base 10).

Sequence in context: A200513 A200523 A118540 * A055959 A341485 A076350

Adjacent sequences: A165107 A165108 A165109 * A165111 A165112 A165113

Keyword

base,nonn

Author

Joseph Myers, Sep 04 2009

Status

approved