A334475 - OEIS

%I #14 Mar 07 2021 10:14:41

%S 0,0,1,1,0,0,1,2,2,3,3,2,3,3,2,1,0,0,1,1,0,0,1,2,2,3,4,4,5,5,4,4,5,6,

%T 6,7,7,6,7,7,6,5,4,5,4,4,5,6,7,7,6,6,7,7,6,5,5,4,3,2,3,3,2,1,0,0,1,1,

%U 0,0,1,2,2,3,3,2,3,3,2,1,0,0,1,1,0,0,1

%N a(n) is the X-coordinate of the n-th point of the space filling curve T defined in A334474; sequence A334476 gives Y-coordinates.

%H Rémy Sigrist, <a href="/A334475/b334475.txt">Table of n, a(n) for n = 0..8255</a>

%H Hugo Pfoertner, <a href="/plot2a?name1=A334475&amp;name2=A334476&amp;tform1=untransformed&amp;tform2=untransformed&amp;shift=0&amp;radiop1=xy&amp;drawlines=true">Illustration of curve T</a>, using Plot 2.

%H Rémy Sigrist, <a href="/A334475/a334475.gp.txt">PARI program for A334475</a>

%H <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a>

%F A334474(A334476(n), a(n)) = n.

%e The space filling curve T starts as follows:

%e     5|  ...

%e      |   |

%e      |   |

%e     4|  16

%e      |   \

%e      |    \

%e     3|   5 15-14-13

%e      |   |\       |

%e      |   | \      |

%e     2|   4  6 11-12

%e      |    \  \  \

%e      |     \  \  \

%e     1|   1  3  7 10

%e      |   |\ |  |  |

%e      |   | \|  |  |

%e     0|   0  2  8--9

%e   ---+-------------

%e   y/x|   0  1  2  3

%e - hence a(2) = a(3) = a(6) = a(15) = 1.

%o (PARI) See Links section.

%Y Cf. A334474, A334476.

%K nonn

%O 0,8

%A _Rémy Sigrist_, May 02 2020