A317106 - OEIS

%I #15 Aug 14 2018 09:02:17

%S 1,27,13,5,11,7,15,9,19,3,17,33,55,85,25,29,51,47,21,39,63,95,57,87,

%T 125,49,23,41,67,35,59,89,53,31,61,37,69,43,77,113,71,45,73,107,149,

%U 101,141,189,135,181,129,91,137,97,65,105,147,99,139,93,131,177,231

%N Squares visited by a (1,3)-leaper on a spirally numbered board and moving to the lowest available unvisited square at each step.

%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 3723, square 7081 is visited, after which there are no unvisited squares within one move.

%H Daniël Karssen, <a href="/A317106/b317106.txt">Table of n, a(n) for n = 1..3723</a>

%H Daniël Karssen, <a href="/A317106/a317106.svg">Figure showing the first 46 steps of the sequence</a>

%H Daniël Karssen, <a href="/A317106/a317106_1.svg">Figure showing the complete sequence</a>

%F a(n) = A317105(n-1) + 1.

%Y Cf. A317105, A317108.

%K nonn,fini,full

%O 1,2

%A _Daniël Karssen_, Jul 24 2018