CUHK MATH Perko Knot
Tie me up, Tie me down
 
Equivalence
Trefoil
Figure Eight
Whitehead
Trivial Knot
Perko Pairs
 
Classifications
Torus Knots
Alternating Knots
 
Invariants
Crossing number
Bridge number
Unknotting number
Tricolorability
Linking number
Polynomials

The Perko Pair

They are the same!!

In a table of knots done by Prof C N Little in 1899, these two knots are listed as different knots. People believe this for 75 years. It was finally discovered by a New York lawyer Kenneth Perko that they are actually the same.

Can you see why?