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 A068609 #24 Jun 04 2019 02:49:27 %S A068609 1,14,5,20,23,10,3,16,19,22,9,12,15,18,7,24,11,4,17,6,21,8,25,2,13,58, %T A068609 33,62,37,68,41,72,75,46,79,50,27,54,31,60,35,64,67,40,71,74,45,78,49, %U A068609 52,29,56,59,34,63,66,39,70,43,76 %N A068609 Path of a knight's tour on an infinite chessboard. %C A068609 One of eight possible knight's tours. Squares are numbered in a clockwise spiral. Enumerates all positive integers. %H A068609 Hugo Pfoertner, <a href="/A068609/b068609.txt">Table of n, a(n) for n = 0..1088</a> [Offset adapted by _Georg Fischer_, Jun 04 2019] %H A068609 Frank Ellermann, <a href="http://oeis.org/A068225/a068225.html">Sequences based on a spiral of the natural numbers</a> %Y A068609 Cf. A068608, A068610, A068611, A068612, A068613, A068614, A068615. %K A068609 nonn %O A068609 0,2 %A A068609 Hans Secelle and Albrecht Heeffer (albrecht.heeffer(AT)pandora.be), Mar 09 2002 %E A068609 a(56), which had been shown as 37, corrected to 39 by Kevin Ryde, Jan 17 2012