A334235 - OEIS

%I #9 Apr 27 2020 23:58:46

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

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

%U 3,3,3,3,4,4,4,4,5,5,6,6,7,7,7,7,6,6,5

%N a(n) is the X-coordinate of the point at n steps backward from the origine along the H-order curve defined in A334232; sequence A334236 gives Y-coordinates.

%H Rémy Sigrist, <a href="/A334235/b334235.txt">Table of n, a(n) for n = 0..8192</a>

%H Rémy Sigrist, <a href="/A334235/a334235.gp.txt">PARI program for A334235</a>

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

%F A334232(A334236(n), a(n)) = -n.

%e The "backward" branch of H-order curve starting from the origin is as follows:

%e     7|  -15..-16  -19..-20  -27..-28  -31

%e      |    |    |    |    |    |    |    |

%e     6|  -14  -17..-18  -21  -26  -29..-30

%e      |    |              |    |

%e     5|  -13  -10...-9  -22  -25

%e      |    |    |    |    |    |

%e     4|  -12..-11   -8  -23..-24

%e      |              |

%e     3|   -3...-4   -7

%e      |    |    |    |

%e     2|   -2   -5...-6

%e      |    |

%e     1|   -1

%e      |    |

%e     0|    0

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

%e   y/x|    0    1    2    3    4    5    6    7

%e - hence a(24) = a(25) = a(26) = a(27) = 4.

%o (PARI) See Links section.

%Y Cf. A334232, A334236.

%K nonn

%O 0,7

%A _Rémy Sigrist_, Apr 20 2020