A054938 Number of chiral chord diagrams on n nodes.

0, 0, 0, 1, 26, 348, 4466, 61726, 949795, 16331482, 312298796, 6587217199, 152030203190, 3811719561156, 103171205826822, 2998417379370294, 93127344062857976, 3078376281077418971, 107905190923235526392

Offset: 1

Author

N. J. A. Sloane, May 24 2000

Keywords

• nonn
• easy

Links

• V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.

Formula

a(n) = A054499(n)-A018191(n). [Liskovets, referring to offset 1 in A054499]. - R. J. Mathar, Oct 01 2011