The command Sequence(x^(2 r) + y^(2 r) = 1, r, 1, 20) doesn't compute the implicit curves for r >= 4, r even. Only x^2 + y^2 = 1 appears. Thanks!
and Sequence(x^(2k) + y^(2k) = 1, k, 20, 1, -1) works but zoom freezes the pc
a little bug here
Objects must be the same type in a list. x^2+y^2=1 is a conic; the others aren't
Michael, but the @mathmagic solution works with x^2 + y^2 = 1 included. It seems GeoGebra only checks the first elements of the list ...
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