A317184 Number of "non-connected" chord diagrams of degree n.

0, 1, 3, 12, 74, 647, 6961, 89739, 1337152, 22609111, 427604861, 8945156182, 205080060435, 5113424483894, 137759755603055, 3987742282544259, 123430664010624370, 4067922952436728611, 142218912116692593949

Offset

1,3

Links

Table of n, a(n) for n=1..19.

Alexander Stoimenow, On the number of chord diagrams, Discr. Math. 218 (2000), 209-233.

Mathematica

Stoimenow states that a Mma package is available from his website.

Crossrefs

Cf. A005034, A018225.

Sequence in context: A246382 A104028 A074510 * A342599 A291951 A176408

Adjacent sequences: A317181 A317182 A317183 * A317185 A317186 A317187

Keyword

nonn

Author

N. J. A. Sloane, Jul 26 2018

Extensions

More terms from Sean A. Irvine, Feb 04 2019

Status

approved