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 A326757 #16 Jan 08 2022 12:28:53 %S A326757 0,0,2,1,1,0,4,0,4,2,1,3,0,5,0,6,2,1,3,4,7,3,5,0,6,2,1,3,1,3,7,6,9,1, %T A326757 5,6,4,1,3,2,9,2,1,8,11,3,1,4,13,12,8,0,4,2,7,9,1,14,2,6,8,4,0,3,12,8, %U A326757 10,2,4,12,5,18,3,7,0,9,4,2,10,8,3,5,7,0 %N A326757 a(n) is the X-coordinate of the n-th nonattacking queen placed by a greedy algorithm on N^3 (see Comments for details). %C A326757 We consider an infinite chessboard on N^3 (the first octant of Z^3) traversed by increasing x+y+z and then increasing x+y and then increasing x and place nonattacking queens as soon as possible; these queens can attack along the 13 axes of rotation of a cube. %C A326757 This sequence is a 3-dimensional variant of A275901. %H A326757 Rémy Sigrist, <a href="/A326757/b326757.txt">Table of n, a(n) for n = 0..10000</a> %H A326757 Rémy Sigrist, <a href="/A326757/a326757.gp.txt">PARI program for A326757</a> %H A326757 Rémy Sigrist, <a href="https://practical-ardinghelli-959d8f.netlify.app/a326757">Interactive scatterplot of the first 25000 queens</a> %e A326757 The traversal of N^3 starts: %e A326757 X Y Z %e A326757 - - - %e A326757 0 0 0 %e A326757 0 0 1 %e A326757 0 1 0 %e A326757 1 0 0 %e A326757 0 0 2 %e A326757 0 1 1 %e A326757 1 0 1 %e A326757 0 2 0 %e A326757 1 1 0 %e A326757 2 0 0 %e A326757 0 0 3 %e A326757 0 1 2 %e A326757 1 0 2 %e A326757 ... %e A326757 The first queen is placed at position (0, 0, 0) and attacks every position (m*i, m*j, m*k) with max(i, j, k) = 1 and m > 0. %e A326757 The second queen is placed at position (0, 1, 2). %o A326757 (PARI) See Links section. %Y A326757 See A326758 and A326759 for the Y- and Z- coordinates, respectively. %Y A326757 Cf. A275901. %K A326757 nonn %O A326757 0,3 %A A326757 _Rémy Sigrist_ and _N. J. A. Sloane_, Jul 23 2019