A018193 Number of chord diagrams of degree n with an isolated chord of length 1.

1, 1, 3, 11, 69, 602, 6531, 84737, 1271143, 21623667, 411133711, 8639077230, 198801435313, 4972210166209, 134299831740091, 3895950849227855, 120808412263797173, 3987662458459383826, 139598735205063044939

Offset: 1

Author

Alexander Stoimenow (stoimeno(AT)math.toronto.edu)

Keywords

• nonn

Links

• D. Bar-Natan, On the Vassiliev Knot Invariants, Topology 34 (1995) 423-472.
• D. Bar-Natan, Bibliography of Vassiliev Invariants
• Alexander Stoimenow, On the number of chord diagrams, Discr. Math. 218 (2000), 209-233.

Programs

Mathematica

Stoimenow states that a Mma package is available from his website. - N. J. A. Sloane, Jul 26 2018

Extensions

More terms from Sean A. Irvine, Feb 04 2019