The Perko pair is a pair of knot diagrams which can be found in the early knot tables. Subsequently the two diagrams were shown to represent the same knot. You may come across as many as three different versions of the Perko pair in the literature. This is because after the early tables were created subsequent authors reproduced them using different diagrams. Here is Perko's isotopy from 105II to 106VI as they appeared in the early tables.
If you have access to JSTOR Perko's paper can be found here

Kenneth A. Perko, Jr. Proceedings of the American Mathematical Society, Vol. 45, No. 2. (Aug., 1974), pp. 262-266.