Triangle read by rows: T(n,k) is the number of linear chord diagrams on 2n vertices with one marked chord such that exactly k of the remaining n-1 chords cross the marked chord.

A336598

Triangle read by rows: T(n,k) is the number of linear chord diagrams on 2n vertices with one marked chord such that exactly k of the remaining n-1 chords cross the marked chord.

Terms

    a(0) =1a(1) =4a(2) =2a(3) =21a(4) =18a(5) =6a(6) =144a(7) =156a(8) =96a(9) =24a(10) =1245a(11) =1500a(12) =1260a(13) =600a(14) =120a(15) =13140a(16) =16470a(17) =16560a(18) =11160a(19) =4320a(20) =720a(21) =164745a(22) =207270a(23) =231210a(24) =194040a(25) =108360a(26) =35280a(27) =5040a(28) =2399040a(29) =2976120

External references