Unknotting number one for the 11 unresolved crossing-neighbor knots

Determine whether each of the 11 distinct non-alternating crossing neighbors arising from the remaining 22 alternating knots has unknotting number one, in order to resolve the corresponding candidate crossings and improve the unknotting-number bounds of the parent knots.

Background

After excluding all crossing changes to unknotting-number-one knots for 959 alternating knots, the authors identify 22 additional alternating diagrams with at least one candidate crossing. These candidates lead to 11 distinct non-alternating knots whose recorded ranges are [1,2] or [1,3]. Establishing or excluding unknotting number one for these neighbors would respectively provide matching upper bounds for, or eliminate candidate crossings from, the parent knots.

References

For each crossing neighbor, it remains to determine whether its unknotting number is one.

Computation of unknotting numbers: which knot breaks the Bernhard-Jablan Conjecture  (2609.09861 - Lee, 9 Sep 2026) in Section 3.2, Alternating Examples