Number of chord-connected permutations on [n].

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =13a(5) =74a(6) =544a(7) =4458a(8) =41221a(9) =421412a(10) =4722881a(11) =57553440a(12) =757741476a(13) =10719973224a(14) =162203047672