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 A068612 #18 Jun 04 2019 02:50:36 %S A068612 1,20,5,14,11,24,7,18,15,12,9,22,19,16,3,10,23,6,17,4,13,2,25,8,21,72, %T A068612 41,68,37,62,33,58,55,28,51,80,47,76,43,70,39,66,63,34,59,56,29,52,49, %U A068612 78,45,74,71,40,67,64,35,60,31,54 %N A068612 Path of a knight's tour on an infinite chessboard. %C A068612 One of eight possible knight's tours. Squares are numbered in a clockwise spiral. Enumerates all positive integers. %H A068612 Hugo Pfoertner, <a href="/A068612/b068612.txt">Table of n, a(n) for n = 0..1088</a> [Offset adapted by _Georg Fischer_, Jun 04 2019] %H A068612 Frank Ellermann, <a href="http://oeis.org/A068225/a068225.html">Sequences based on a spiral of the natural numbers</a> %Y A068612 Cf. A068608, A068609, A068610, A068611, A068613, A068614, A068615. %K A068612 nonn %O A068612 0,2 %A A068612 Hans Secelle and Albrecht Heeffer (albrecht.heeffer(AT)pandora.be), Mar 09 2002