AS159 and AS173 are an exact match from the area between Ica and Pisco. This pair was first discovered by the Aschers and is published in their databook of 1987. (See References). Values such as 18+2 or 16+1 indicate an anomalous arrangement of knots: either two long knots or a long knot and an E knot. The pages on Khipu Construction have more information about knot types and their values.