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 A330782 #19 Feb 25 2020 21:53:26 %S A330782 1,2,8,32,40,68,98,148,162,356,450 %N A330782 The records for distance squared for step lengths between adjacent composite numbers in A332767, the visited composite numbers for a walk stepping to the closest unvisited composite number on the 2D square (Ulam) spiral. %C A330782 The sequence A332767 gives the visited composite numbers for a walk on the 2D square (Ulam) spiral which starts at 1 and then steps to the square containing the closest unvisited composite number. This sequences lists the records for the square of the step distance between visited composite numbers for that walk. For a walk of 1 million steps the largest square distance is 450, approximately 21.1 units, which occurs between A332767(149464) = 64666, which has coordinates (-127,-22) relative to the starting 1-square, to A332767(149465) = 67774 with coordinates (-130,-43). See A332767 for an image of the walk. It is unknown if this is a finite or infinite sequence. %H A330782 Wikipedia, <a href="https://en.wikipedia.org/wiki/Ulam_spiral">Ulam Spiral</a>. %e A330782 The below table shows the details of the record step lengths of this sequence for the first 1 million steps. The coordinate is relative to the starting 1-square. %e A330782 -------------------------------------------------------------------------------- %e A330782 a(n) | A332767 step # | Start value & coord | End value & coord | %e A330782 -------------------------------------------------------------------------------- %e A330782 1 | 1 | 1 (0,0) | 4 (0,1) | %e A330782 2 | 6 | 32 (2,3) | 30 (3,2) | %e A330782 8 | 154 | 74 (-3,-4) | 158 (-5,-6) | %e A330782 32 | 4501 | 5526 (-37,-12) | 6782 (-41,-16) | %e A330782 40 | 65877 | 48150 (110,79) | 53558 (116,81) | %e A330782 68 | 91787 | 126154 (178,-49) | 137780 (186,-47) | %e A330782 98 | 125472 | 145762 (-28,191) | 156654 (-35,198) | %e A330782 148 | 142733 | 105316 (-147,-162) | 102746 (-135,-160) | %e A330782 162 | 142741 | 92744 (-129,-152) | 82106 (-120,-143) | %e A330782 356 | 142869 | 67818 (-130,-87) | 57792 (-120,-71) | %e A330782 450 | 149464 | 64666 (-127,-22) | 67774 (-130,-43) | %Y A330782 Cf. A332767, A330979, A331027, A000040, A063826, A136626. %K A330782 nonn,walk,more %O A330782 1,2 %A A330782 _Scott R. Shannon_, Feb 23 2020