cp's OEIS Frontend

A317415 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 >=0.

%I A317415 #12 Feb 06 2025 04:09:58
%S A317415 0,51,22,13,24,19,10,17,12,23,14,21,16,11,18,9,20,15,28,5,26,31,8,33,
%T A317415 6,25,44,3,46,41,66,107,148,35,40,1,38,43,4,27,56,85,2,37,32,7,34,29,
%U A317415 50,45,70,103,142,95,64,39,62,93,130,175,122,47,74,117,160,155,106,65
%N A317415 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 >=0.
%C A317415 Board is numbered with the square spiral:
%C A317415 .
%C A317415   16--15--14--13--12
%C A317415    |               |
%C A317415   17   4---3---2  11   .
%C A317415    |   |       |   |
%C A317415   18   5   0---1  10   .
%C A317415    |   |           |
%C A317415   19   6---7---8---9   .
%C A317415    |
%C A317415   20--21--22--23--24--25
%C A317415 .
%C A317415 The sequence is finite: at step 13102, square 10846 is visited, after which there are no unvisited squares within one move.
%H A317415 Daniël Karssen, <a href="/A317415/b317415.txt">Table of n, a(n) for n = 0..13102</a>
%H A317415 Daniël Karssen, <a href="/A317415/a317415.svg">Figure showing the first 58 steps of the sequence</a>
%H A317415 Daniël Karssen, <a href="/A317415/a317415_1.svg">Figure showing the complete sequence</a>
%F A317415 a(n) = A317416(n+1) - 1.
%Y A317415 Cf. A317416, A317417.
%K A317415 nonn,fini,full
%O A317415 0,2
%A A317415 _Daniël Karssen_, Jul 27 2018