ref : Hans Lauwerier, Fractals : Endlessly Repeated Geometrical Figures, Princeton Science Library (1991).

Algorithme

Pick a0, x0, y0 Pick B close to 1.0 a = a0 c = 2 - 2 * a x = x0 y = y0 w = a * x + c * x * x / (1 + x * x) do: skip first 100 iterations Plot x, y z = x x = B * y + w u = x * x w = a * x + c * u / (1 + u) y = w - z loop