cp's OEIS Frontend

A317105 Squares visited by a (1,3)-leaper on a spirally numbered board and moving to the lowest available unvisited square at each step, squares labelled >=0.

%I A317105 #22 Feb 06 2025 04:11:40
%S A317105 0,26,12,4,10,6,14,8,18,2,16,32,54,84,24,28,50,46,20,38,62,94,56,86,
%T A317105 124,48,22,40,66,34,58,88,52,30,60,36,68,42,76,112,70,44,72,106,148,
%U A317105 100,140,188,134,180,128,90,136,96,64,104,146,98,138,92,130,176,230
%N A317105 Squares visited by a (1,3)-leaper on a spirally numbered board and moving to the lowest available unvisited square at each step, squares labelled >=0.
%C A317105 Board is numbered with the square spiral:
%C A317105 .
%C A317105   16--15--14--13--12
%C A317105    |               |
%C A317105   17   4---3---2  11   .
%C A317105    |   |       |   |
%C A317105   18   5   0---1  10   .
%C A317105    |   |           |
%C A317105   19   6---7---8---9   .
%C A317105    |
%C A317105   20--21--22--23--24--25
%C A317105 .
%C A317105 The sequence is finite: at step 3722, square 7080 is visited, after which there are no unvisited squares within one move.
%H A317105 Daniël Karssen, <a href="/A317105/b317105.txt">Table of n, a(n) for n = 0..3722</a>
%H A317105 Daniël Karssen, <a href="/A317105/a317105.svg">Figure showing the first 46 steps of the sequence</a>
%H A317105 Daniël Karssen, <a href="/A317105/a317105_1.svg">Figure showing the complete sequence</a>
%F A317105 a(n) = A317106(n+1) - 1.
%Y A317105 Cf. A317106, A317107.
%K A317105 nonn,fini,full
%O A317105 0,2
%A A317105 _Daniël Karssen_, Jul 24 2018, following a suggestion from _N. J. A. Sloane_, Jul 15 2018