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 A165027 #9 Jun 02 2025 01:56:26 %S A165027 1,0,1,1,0,3,1,3,3,5,3,8,5,9,8,12,9,16,12,18,16,22,18,27,22,30,27,35, %T A165027 30,41,35,45,41,51,45,58,51,63,58,70,63,78,70,84,78,92,84,101,92,108, %U A165027 101,117,108,127,117,135,127,145,135,156,145,165,156,176,165,188,176,198 %N A165027 Number of n-digit fixed points under the base-4 Kaprekar map A165012. %H A165027 Joseph Myers, <a href="/A165027/b165027.txt">Table of n, a(n) for n=1..200</a> %H A165027 <a href="/index/K#Kaprekar_map">Index entries for the Kaprekar map</a> %F A165027 Conjectures from _Chai Wah Wu_, Apr 13 2024: (Start) %F A165027 a(n) = 2*a(n-2) + a(n-3) - a(n-4) - 2*a(n-5) + a(n-7) for n > 8. %F A165027 G.f.: x*(x^7 - x^6 - 2*x^5 + x^4 + x^2 - 1)/((x - 1)^3*(x + 1)^2*(x^2 + x + 1)). (End) %Y A165027 Cf. A165012, A165016, A165025, A165026. %Y A165027 In other bases: A004526 (base 2, adjusted to start 1, 0, 0, 1, 1, ...), A008615 (base 3), A008617 (base 5), A165066 (base 6), A008722 (base 7, conjecturally), A165105 (base 8), A165125 (base 9), A164733 (base 10). %K A165027 base,nonn %O A165027 1,6 %A A165027 _Joseph Myers_, Sep 04 2009