Triangle T(i,j) read by rows: Number of plane bipolar orientations with i+1 vertices and j+1 faces.

Terms

a(0) =1a(1) =1a(2) =4a(3) =1a(4) =10a(5) =50a(6) =1a(7) =20a(8) =175a(9) =980a(10) =1a(11) =35a(12) =490a(13) =4116a(14) =24696a(15) =1a(16) =56a(17) =1176a(18) =14112a(19) =116424a(20) =731808a(21) =1a(22) =84a(23) =2520a(24) =41580a(25) =457380a(26) =3737448a(27) =24293412a(28) =1a(29) =120