This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A307285 #10 Oct 27 2019 11:15:42 %S A307285 0,3,6,10,15,20,23,27,30,33,39,44,47,50,53,56,59,62,65,70,73,76,79,82, %T A307285 85,88,91,94,99,102,105,110,113,116,119,122,125,130,133,136,139,142, %U A307285 147,150,153,158,161,164,169,172,175,178,181,184,189,192,195,198,201 %N A307285 Coordinates Y_upper(n) of P-positions in Maharaja Nim on square spiral (see Comments for precise definition). %C A307285 We study Maharaja Nim on the square spiral, as in A307282, A307283, and in particular the P-positions in the 4th quadrant. As in A140100 and A140101 (which are the analogs if we use a Queen instead of a Maharaja) we take the X-axis to point South and the Y-axis to point East. %C A307285 The P-positions now lie on two roughly straight lines, with coordinates (X_upper(n), Y_upper(n)) with X_upper(n) <= Y_upper(n), and (X_lower(n), Y_lower(n)) with X_lower(n) <= Y_lower(n). These four sequences are A307284-A307287. %C A307285 The two lines are the hard-to-see black pixels in the fourth quadrant in the Sigrist illustration. %H A307285 Rémy Sigrist, <a href="/A307282/a307282_1.png">Colored representation of the spiral for x = -500..500 and y = -500..500</a> (where the hue is function of T(x,y) and black pixels correspond to 0's) %Y A307285 Cf. A140100, A140101, A307282, A307283, A307284-A307287. %K A307285 nonn %O A307285 0,2 %A A307285 _N. J. A. Sloane_, Apr 08 2019