Number of decomposable fixed-point free involutions, also the number of disconnected chord diagrams with 2n nodes on an open string.
A177797
Number of decomposable fixed-point free involutions, also the number of disconnected chord diagrams with 2n nodes on an open string.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =5a(4) =31a(5) =239a(6) =2233a(7) =24725a(8) =318631a(9) =4707359a(10) =78691633a(11) =1471482725a(12) =30469552111a(13) =692488851599
External references
- oeis: A177797