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%I #11 Apr 27 2020 23:58:12
%S 0,1,2,3,3,2,1,1,2,3,4,4,4,5,6,7,7,6,5,5,6,7,7,6,5,4,3,3,4,5,6,7,7,6,
%T 5,5,6,7,8,8,8,9,10,10,9,8,8,8,8,9,10,11,11,10,9,9,10,11,12,12,12,13,
%U 14,15,15,14,13,13,14,15,15,14,13,12,11,11,12,13
%N a(n) is the Y-coordinate of the point at n steps backward from the origine along the space filling curve U defined in A334188; sequence A334222 gives X-coordinates.
%H Rémy Sigrist, <a href="/A334223/b334223.txt">Table of n, a(n) for n = 0..8318</a>
%H Rémy Sigrist, <a href="/A334223/a334223.gp.txt">PARI program for A334223</a>
%H <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a>
%F A334188(a(n), A334223(n)) = -n.
%e The "backward" branch of curve U starting from the origin is as follows:
%e | |
%e 7| -15..-16 -21..-22 -31..-32 -37
%e | | | | | | | |
%e 6| -14 -17 -20 -23 -30 -33 -36
%e | | | | | | | |
%e 5| -13 -18..-19 -24 -29 -34..-35
%e | | | |
%e 4| -12..-11..-10 -25 -28
%e | | | |
%e 3| -3...-4 -9 -26..-27
%e | | | |
%e 2| -2 -5 -8
%e | | | |
%e 1| -1 -6...-7
%e | |
%e 0| 0
%e ---+-----------------------------------
%e y/x| 0 1 2 3 4 5 6
%e - hence a(10) = a(11) = a(12) = a(25) = a(28) = 4.
%o (PARI) See Links section.
%Y Cf. A334188, A334222.
%K nonn
%O 0,3
%A _Rémy Sigrist_, Apr 19 2020