A293922 Number of linear chord diagrams having n chords and minimal chord length nine.

1, 639, 69676, 4100988, 184283856, 7306919616, 275875184700, 10345618038532, 394140369614751, 15439822086531614, 625906719760828175, 26339564820084748490, 1152078058596976970932, 52386933718575091061064, 2475581777015155231108104, 121493777824620584462513636

Offset

9,2

Links

Alois P. Heinz, Table of n, a(n) for n = 9..200

Formula

a(n) ~ (exp(-8) - exp(-9)) * 2^(n + 1/2) * n^n / exp(n). - Vaclav Kotesovec, Oct 25 2017

Crossrefs

Column k=9 of A293881.

Sequence in context: A200710 A250661 A250587 * A027885 A097105 A233911

Adjacent sequences: A293919 A293920 A293921 * A293923 A293924 A293925

Keyword

nonn

Author

Alois P. Heinz, Oct 19 2017

Status

approved