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 A053394 #19 Mar 10 2020 13:56:38 %S A053394 1,297,703,999 %N A053394 The full list of 3-Kaprekar numbers. %H A053394 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 A053394 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a> %Y A053394 Cf. A006886, A037042, A053395, A053396, A053397, A333133. %K A053394 nonn,fini,full,base %O A053394 1,2 %A A053394 _N. J. A. Sloane_, Jan 07 2000