| Cinquefoil | |
|---|---|
 | |
| Common name | Double overhand knot |
| Arf invariant | 1 |
| Braid length | 5 |
| Braid no. | 2 |
| Bridge no. | 2 |
| Crosscap no. | 1 |
| Crossing no. | 5 |
| Genus | 2 |
| Hyperbolic volume | 0 |
| Stick no. | 8 |
| Unknotting no. | 2 |
| Conway notation | [5] |
| A–B notation | 51 |
| Dowker notation | 6, 8, 10, 2, 4 |
| Last / Next | 41 / 52 |
| Other | |
| alternating, torus, fibered, prime, reversible | |
In knot theory, the cinquefoil knot, also known as Solomon's seal knot or the pentafoil knot, is one of two knots with crossing number five, the other being the three-twist knot. It is listed as the 51 knot in the Alexander-Briggs notation, and can also be described as the (5,2)-torus knot. The cinquefoil is the closed version of the double overhand knot.