A293916 Number of linear chord diagrams having n chords and minimal chord length three.

1, 9, 79, 854, 11105, 167273, 2855096, 54426601, 1146050151, 26418261876, 661704149855, 17894827830455, 519672858520861, 16129429179859894, 532839970205194270, 18667063990244959414, 691265187531408182336, 26979801565685043088417, 1106929654165005908000185

Offset: 3

Author

Alois P. Heinz, Oct 19 2017

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 3..404

Crossrefs

Column k=3 of A293881.

Formula

a(n) ~ (exp(-2) - exp(-3)) * 2^(n + 1/2) * n^n / exp(n). - Vaclav Kotesovec, Oct 25 2017