A prime link is a link that cannot be represented as a knot sum of other links. Doll and Hoste (1991) list polynomials for oriented links of nine or fewer crossings, and Rolfsen (1976) gives a table of links with small numbers of components and crossings.
The following table summarizes the number of distinct prime -components links having specified crossing numbers. The
components | OEIS | prime -component links with 1, 2, ... crossings |
1 | A002863 | 0, 0, 1, 1, 2, 3, 7, 21, 49, 165, 552, ... |
2 | A048952 | 0, 1, 0, 1, 1, 3, 8, 16, 61, 185, 638, ... |
3 | A048953 | 0, 0, 0, 0, 0, 3, 1, 10, 21, 74, 329, ... |
4 | A087071 | 0, 0, 0, 0, 0, 0, 0, 3, 1, 15, 39, ... |
5 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 1, ... | |
total | A086771 | 0, 1, 1, 2, 3, 9, 16, 50, 132, 442, 1559, ... |
The following table lists some named links. The notation and ordering follows that of Rolfsen (1976), where denotes the th -component link with crossing number .
link number | name |
unlink | |
Hopf link | |
Whitehead link | |
Borromean rings |
A listing of the first few simple links follows, arranged by link crossing number.
01
01
01
01
01 02 03
01 02 03 04 05 06 07 08
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
01 02 03
01
01 02 03 04 05 06 07 08 09 10
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21
01 02 03
01