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a(n) is the Y-coordinate of the point at n steps backward from the origine along the H-order curve defined in A334232; sequence A334235 gives X-coordinates.
3

%I #9 Apr 27 2020 23:58:52

%S 0,1,2,3,3,2,2,3,4,5,5,4,4,5,6,7,7,6,6,7,7,6,5,4,4,5,6,7,7,6,6,7,8,9,

%T 9,8,8,9,10,11,11,10,9,8,8,9,9,8,8,9,10,11,11,10,10,11,12,13,13,12,12,

%U 13,14,15,15,14,14,15,15,14,13,12,12,13,14,15,15

%N a(n) is the Y-coordinate of the point at n steps backward from the origine along the H-order curve defined in A334232; sequence A334235 gives X-coordinates.

%H Rémy Sigrist, <a href="/A334236/b334236.txt">Table of n, a(n) for n = 0..8192</a>

%H Rémy Sigrist, <a href="/A334236/a334236.gp.txt">PARI program for A334236</a>

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

%F A334232(a(n), A334235(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(28) = a(29) = 5.

%o (PARI) See Links section.

%Y Cf. A334232, A334235.

%K nonn

%O 0,3

%A _Rémy Sigrist_, Apr 20 2020