A317416 - OEIS

%I #11 Feb 06 2025 04:10:22

%S 1,52,23,14,25,20,11,18,13,24,15,22,17,12,19,10,21,16,29,6,27,32,9,34,

%T 7,26,45,4,47,42,67,108,149,36,41,2,39,44,5,28,57,86,3,38,33,8,35,30,

%U 51,46,71,104,143,96,65,40,63,94,131,176,123,48,75,118,161,156,107,66

%N Squares visited by a (1,4)-leaper on a spirally numbered board and moving to the lowest available unvisited square at each step, squares labelled >=1.

%C Board is numbered with the square spiral:

%C .

%C   17--16--15--14--13

%C    |               |

%C   18   5---4---3  12   .

%C    |   |       |   |

%C   19   6   1---2  11   .

%C    |   |           |

%C   20   7---8---9--10   .

%C    |

%C   21--22--23--24--25--26

%C .

%C The sequence is finite: at step 13103, square 10847 is visited, after which there are no unvisited squares within one move.

%H Daniël Karssen, <a href="/A317416/b317416.txt">Table of n, a(n) for n = 1..13103</a>

%H Daniël Karssen, <a href="/A317416/a317416.svg">Figure showing the first 58 steps of the sequence</a>

%H Daniël Karssen, <a href="/A317416/a317416_1.svg">Figure showing the complete sequence</a>

%F a(n) = A317415(n-1) + 1.

%Y Cf. A317415, A317418.

%K nonn,fini,full

%O 1,2

%A _Daniël Karssen_, Jul 27 2018