This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A069746 #11 Mar 01 2015 15:11:26 %S A069746 1000,1011,1101,1110,1111,1112,1121,1211,1222,2111,2122,2212,2221, %T A069746 2222,2223,2232,2322,2333,3222,3233,3323,3332,3333,3334,3343,3433, %U A069746 3444,4333,4344,4434,4443,4444,4445,4454,4544,4555,5444,5455,5545,5554,5555,5556 %N A069746 Four-digit numbers that do not resolve to 6174 under the Kaprekar map (see A151949). %C A069746 Dinesh Thakur (email, Mar 01 2015) points out that Kaprekar himself would pad numbers with fewer than four digits by adding initial zeros, so that for him the only four-digit exceptions are those with all four digits equal. - _N. J. A. Sloane_, Mar 01 2015 %H A069746 Joseph Myers, <a href="/A069746/b069746.txt">Table of n, a(n) for n=1..77</a> (the full list) %H A069746 <a href="/index/K#Kaprekar_map">Index entries for the Kaprekar map</a> %Y A069746 Cf. A151949. %K A069746 fini,full,nonn,base %O A069746 1,1 %A A069746 _Harvey P. Dale_, Apr 22 2002 %E A069746 There are precisely 77 such numbers.