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 A053397 #21 Mar 10 2020 10:04:15 %S A053397 1,5292,38962,142857,148149,181819,187110,208495,318682,329967,351352, %T A053397 356643,390313,461539,466830,499500,500500,533170,538461,609687, %U A053397 643357,648648,670033,681318,791505,812890,818181,851851,857143,961038,994708,999999 %N A053397 The full list of 6-Kaprekar numbers. %H A053397 D. E. Iannucci, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL3/iann2a.html">The Kaprekar numbers</a>, J. Integer Sequences, Vol. 3, 2000, #1.2. %H A053397 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a> %Y A053397 Cf. A006886, A037042, A053394, A053395, A053396, A333133. %K A053397 nonn,fini,full,base %O A053397 1,2 %A A053397 _N. J. A. Sloane_, Jan 07 2000