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 A068613 #18 May 10 2019 17:07:32 %S A068613 1,24,7,18,15,12,9,22,19,16,3,10,23,20,5,14,11,8,21,6,17,4,13,2,25,80, %T A068613 47,76,43,70,39,66,63,34,59,56,29,52,49,78,45,74,71,40,67,64,35,60,31, %U A068613 54,27,50,79,46,75,72,41,68,37,62 %N A068613 Path of a knight's tour on an infinite chessboard. %C A068613 One of eight possible knight's tours. Squares are numbered in a clockwise spiral. Enumerates all positive integers. %H A068613 Hugo Pfoertner, <a href="/A068613/b068613.txt">Table of n, a(n) for n = 0..1088</a> %H A068613 Frank Ellermann, <a href="http://oeis.org/A068225/a068225.html">Sequences based on a spiral of the natural numbers</a> %Y A068613 Cf. A068608, A068609, A068610, A068611, A068612, A068614, A068615. %K A068613 nonn,look %O A068613 0,2 %A A068613 Hans Secelle and Albrecht Heeffer (albrecht.heeffer(AT)pandora.be), Mar 09 2002