Unlabeled super-Catalan numbers: patterns of nonintersecting chords joining unlabeled points on a flippable circle.

A183758

Unlabeled super-Catalan numbers: patterns of nonintersecting chords joining unlabeled points on a flippable circle.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =12a(5) =44a(6) =176a(7) =809a(8) =3883a(9) =19265

External references