A018225 Number of connected chord diagrams of degree n.
1, 1, 2, 6, 31, 255, 2788, 37333, 578799, 10134071, 197394232, 4231417728, 98991987830, 2510081238264, 68583045013542, 2009094843480565, 62824038815664719, 2088829704241946181, 73591470349452760456, 2738742863175749456078
Offset: 1
Keywords
Links
- Alexander Stoimenow, On the number of chord diagrams, Discr. Math. 218 (2000), 209-233.
Programs
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Mathematica
Stoimenow states that a Mma package is available from his website. - N. J. A. Sloane, Jul 26 2018
Formula
Extensions
More terms from Sean A. Irvine, Feb 05 2019