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 A382163 #21 Jul 09 2025 05:08:40 %S A382163 1,9,55,99,999,7777,9999,22222,99999,999999,4444444,9999999,88888888, %T A382163 99999999,909090909,999999999,1111111111,9999999999,55555555555, %U A382163 99999999999,999999999999,7777777777777,9999999999999,22222222222222,99999999999999,999999999999999,4444444444444444,9999999999999999,88888888888888888 %N A382163 Palindromic Kaprekar numbers. %H A382163 Amiram Eldar, <a href="/A382163/b382163.txt">Table of n, a(n) for n = 1..91</a> %H A382163 Shyam Sunder Gupta, <a href="https://doi.org/10.1007/978-981-97-2465-9_9">On Some Marvellous Numbers of Kaprekar</a>, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 9, 275-315. %Y A382163 Intersection of A002113 and A006886. %Y A382163 Cf. A382164. %K A382163 nonn,base %O A382163 1,2 %A A382163 _N. J. A. Sloane_, Mar 26 2025