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A334235 a(n) is the X-coordinate of the point at n steps backward from the origin along the H-order curve defined in A334232; sequence A334236 gives Y-coordinates.

%I A334235 #11 May 06 2025 11:21:22
%S A334235 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 A334235 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 A334235 3,3,3,3,4,4,4,4,5,5,6,6,7,7,7,7,6,6,5
%N A334235 a(n) is the X-coordinate of the point at n steps backward from the origin along the H-order curve defined in A334232; sequence A334236 gives Y-coordinates.
%H A334235 Rémy Sigrist, <a href="/A334235/b334235.txt">Table of n, a(n) for n = 0..8192</a>
%H A334235 Rémy Sigrist, <a href="/A334235/a334235.gp.txt">PARI program for A334235</a>
%H A334235 <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a>
%F A334235 A334232(A334236(n), a(n)) = -n.
%e A334235 The "backward" branch of H-order curve starting from the origin is as follows:
%e A334235     7|  -15..-16  -19..-20  -27..-28  -31
%e A334235      |    |    |    |    |    |    |    |
%e A334235     6|  -14  -17..-18  -21  -26  -29..-30
%e A334235      |    |              |    |
%e A334235     5|  -13  -10...-9  -22  -25
%e A334235      |    |    |    |    |    |
%e A334235     4|  -12..-11   -8  -23..-24
%e A334235      |              |
%e A334235     3|   -3...-4   -7
%e A334235      |    |    |    |
%e A334235     2|   -2   -5...-6
%e A334235      |    |
%e A334235     1|   -1
%e A334235      |    |
%e A334235     0|    0
%e A334235   ---+----------------------------------------
%e A334235   y/x|    0    1    2    3    4    5    6    7
%e A334235 - hence a(24) = a(25) = a(26) = a(27) = 4.
%o A334235 (PARI) See Links section.
%Y A334235 Cf. A334232, A334236.
%K A334235 nonn
%O A334235 0,7
%A A334235 _Rémy Sigrist_, Apr 20 2020