A Brunnian link is a set of linked loops such that each proper sublink is trivial, so that the removal of any component leaves a set of trivial unlinked Unknots. The Borromean Rings are the simplest example and have .
See also Borromean Rings
References
Rolfsen, D. Knots and Links. Wilmington, DE: Publish or Perish Press, 1976.