A note on the OU sequences of a 2-bridge knot

Abstract

An OU sequence is a cyclically ordered sequence in symbols [Formula: see text] and [Formula: see text] such that the number of [Formula: see text]’s is equal to that of [Formula: see text]’s. Every knot diagram defines an O’U sequence by reading [Formula: see text] and [Formula: see text] at over- and under-crossings, respectively, appeared along the diagram. In this note, we determine the OU sequences for a [Formula: see text]-bridge knot arising from its diagrams with two over-bridges.