Endless knot symbol

The "Endless Knot" symbol of Asian cultures (in some versions this is a symbol of Buddhism):

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  Simplest form with 9 crossings, 7 of which are structurally significant (i.e. a 7_4 knot). Photograph of Susan Williams' medallion [1].

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  Form with 25 crossings, 23 of which are structurally significant.

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  Form with 49 crossings, 47 of which are structurally significant. Photograph of ca. 400 year old Chinese lacquerware dish.