71 knot
MATHEMATICAL KNOT WITH CROSSING NUMBER 7
7 1 knot; 7-1 knot; (7,2)-torus knot; 7₁ knot
In knot theory, the 71 knot, also known as the septoil knot, the septafoil knot, or the (7, 2)-torus knot, is one of seven prime knots with crossing number seven. It is the simplest torus knot after the trefoil and cinquefoil.