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A323259 a(n) is the Y-coordinate of the n-th point of the first type of Wunderlich curve (starting at the origin and occupying the first quadrant).

%I A323259 #13 Feb 12 2020 14:17:30
%S A323259 0,0,0,1,1,1,2,2,2,3,4,5,5,4,3,3,4,5,6,6,6,7,7,7,8,8,8,8,7,6,6,7,8,8,
%T A323259 7,6,5,5,5,4,4,4,3,3,3,2,1,0,0,1,2,2,1,0,0,0,0,1,1,1,2,2,2,3,4,5,5,4,
%U A323259 3,3,4,5,6,6,6,7,7,7,8,8,8,9,10,11,11,10
%N A323259 a(n) is the Y-coordinate of the n-th point of the first type of Wunderlich curve (starting at the origin and occupying the first quadrant).
%H A323259 Rémy Sigrist, <a href="/A323259/b323259.txt">Table of n, a(n) for n = 1..6561</a>
%H A323259 <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a>
%o A323259 (PARI) s = [0, 1, 2, 2+I, 1+I, I, 2*I, 1+2*I, 2+2*I];
%o A323259 w = apply(z -> imag(z) + I*real(z), s);
%o A323259 r = [0, 1, 0, 3, 2, 3, 0, 1, 0]
%o A323259 a(n) = {
%o A323259     my (d=if (n>1, Vecrev(digits(n-1, 9)), [0]), z=s[1+d[1]]);
%o A323259     for (i=2, #d,
%o A323259         my (c=(3^(i-1)-1)/2*(1+I));
%o A323259         z = 3^(i-1) * w[1+d[i]] + c + (z-c) * I^r[1+d[i]];
%o A323259     );
%o A323259     return (imag(z));
%o A323259 }
%Y A323259 See A323258 for the X-coordinate and additional comments.
%K A323259 nonn
%O A323259 1,7
%A A323259 _Rémy Sigrist_, Jan 09 2019