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 A165021 #10 Aug 28 2024 13:41:36 %S A165021 0,30,126,201,570,2550,3369,3873,14565,41958,54441,62625,64641,171990, %T A165021 234405,254865,873129,954261,1004193,1036929,1044993,2788950,3755685, %U A165021 4083345,4165185,11140950,13978281,15285909,16075425,16399953,16599681 %N A165021 Consider the base-4 Kaprekar map n->K(n) defined in A165012. Sequence gives least elements of each cycle, including fixed points. %C A165021 Initial terms in base 4: 0, 132, 1332, 3021, 20322, 213312, 310221, 330201, 3203211, 22033212. %H A165021 Joseph Myers, <a href="/A165021/b165021.txt">Table of n, a(n) for n=1..7165</a> %H A165021 Anthony Kay and Katrina Downes-Ward, <a href="https://arxiv.org/abs/2408.12257">Fixed Points and Cycles of the Kaprekar Transformation: 2. Even bases</a>, arXiv:2408.12257 [math.CO], 2024. See p. 16. %H A165021 <a href="/index/K#Kaprekar_map">Index entries for the Kaprekar map</a> %Y A165021 Union of A165016 and A165023. Cf. A165012, A165022, A165017, A165019, A165030, A165025. %Y A165021 In other bases: A163205 (base 2), A165002 (base 3), A165041 (base 5), A165060 (base 6), A165080 (base 7), A165099 (base 8), A165119 (base 9), A164718 (base 10). %K A165021 base,nonn %O A165021 1,2 %A A165021 _Joseph Myers_, Sep 04 2009