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 A164723 #6 Dec 27 2023 21:24:19 %S A164723 53955,59994,8733209876622,9665429654331,873332098766622, %T A164723 966543296654331,8764421997755322,8765431997654322,87333320987666622, %U A164723 96654332966654331,8733333209876666622,9665433329666654331 %N A164723 Numbers belonging to cycles of length 2 under the Kaprekar map A151949. %H A164723 Joseph Myers, <a href="/A164723/b164723.txt">Table of n, a(n) for n=1..1146</a> %H A164723 <a href="/index/K#Kaprekar_map">Index entries for the Kaprekar map</a> %Y A164723 Cf. A151949, A151959, A099009, A099010, A164716, A164725, A164727, A164729, A164724. %K A164723 base,nonn %O A164723 1,1 %A A164723 _Joseph Myers_, Aug 23 2009