A375605 Number of composite knots with n crossings.

0, 0, 0, 0, 0, 0, 2, 1, 5

Offset

0,7

Comments

A knot is composite if and only if it can be written as the knot sum of two nontrivial knots.

Links

Table of n, a(n) for n=0..8.

Formula

a(n) = A086825(n) - A002863(n), for all n > 0.

Example

For n = 6 there are totally 5 knots out of which 3 are prime, so a(6) = 5 - 3 = 2.

Crossrefs

Cf. A086825, A002863.

Sequence in context: A355517 A227050 A093876 * A322334 A198371 A352559

Adjacent sequences: A375602 A375603 A375604 * A375606 A375607 A375608

Keyword

nonn,hard,more,bref

Author

Jens Ahlström, Aug 20 2024

Status

approved