A323470 - OEIS

%I #14 Apr 30 2021 21:23:50

%S -1,2015,3722,13102,14569,26966,101249,158734,132687,220438,144840,

%T 646727,350719,66182,75258,248763,118693,307482,238207,189158,139638,

%U 183820,151015,171075,114186,262234,178611,257631,124474,178861,143673,196794,60706,309819

%N On a spirally numbered square grid, with labels starting at 0, this is the number of the final step that a (1,n) leaper makes before getting trapped, or -1 if it never gets trapped.

%C A (1,2) leaper is a chess knight.

%C a(2)-a(5) were computed by _Daniël Karssen_.

%H Rémy Sigrist, <a href="/A323470/b323470.txt">Table of n, a(n) for n = 1..1000</a>

%H Rémy Sigrist, <a href="/A323470/a323470.txt">C++ program for A323470</a>

%H N. J. A. Sloane and Brady Haran, <a href="https://www.youtube.com/watch?v=RGQe8waGJ4w">The Trapped Knight</a>, Numberphile video (2019)

%o (C++) See Links section.

%Y The sequences involved in this set of related sequences are A316884, A316967, A316667, A316328, A317106, A317105, A317416, A317415, A317438, A317437, and A323469, A323470, A323471, A323472.

%K sign

%O 1,2

%A _N. J. A. Sloane_, Jan 28 2019

%E More terms from _Rémy Sigrist_, Jan 29 2019