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 A333684 #8 Apr 09 2020 22:19:54 %S A333684 72085,706243,270402,236090,716518,716518,730674,657313,236090,236090, %T A333684 1318101,1634797,482448,901595,237177,1946730,21429,726318,706243, %U A333684 730674,793200,237177,405933,3095967,51035,159266,218715,106443,101767,927137,148315,786512,1495770 %N A333684 The cell number where a knight is trapped when moving on a spirally numbered hexagonal board to the lowest available unvisited cell and starting at cell n. %C A333684 For a knight moving on a spirally numbered hexagonal board to the lowest available unvisited cell, see A327131, a(n) gives the cell number where the knight is trapped when the knight starts on the cell numbered n. %C A333684 See A327131 for the allowed knight moves, a diagram of the hexagonal board, and an illustration of the knight's path for n = 1. %C A333684 For the first 100000 terms the largest cell number where the knight is trapped is for starting starting cell 81479 where the final cell has number 8085793, being reached after 8125572 steps. In the same range the smallest cell number where the night is trapped is for starting cell 1036 where the final cell has number 1267, being reached after 1603 steps. See A333683 for an image of this path. %H A333684 N. J. A. Sloane and Brady Haran, <a href="https://www.youtube.com/watch?v=RGQe8waGJ4w">The Trapped Knight</a>, Numberphile video (2019). %e A333684 The knight starting on cell 1 becomes trapped on cell 72085 after 83965 steps, see A327131. %Y A333684 Cf. A333683 (number of steps), A327131, A309918, A328894, A306291. %K A333684 nonn %O A333684 1,1 %A A333684 _Scott R. Shannon_, Apr 02 2020