Remark. Given n consider the set of knots which have a diagram with n crossings but not fewer crossings. Then for n = 3,4,5,6,7 colouring numbers distinguish the knots from each other. But 82 and 83 have the same colouring group Z17. In the next section we will have an invariant which distinguishes these two knots.

8_17 is achiral. A table of knots (up to 10 crossings) and their codes. Some diagrams drawn from their codes. See what Tait had to say about 4.4 and Celtic knots.

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