Triangle read by rows. T(n, k) = ((2*n)! * k!) / (n + k)!.

Terms

a(0) =1a(1) =2a(2) =1a(3) =12a(4) =4a(5) =2a(6) =120a(7) =30a(8) =12a(9) =6a(10) =1680a(11) =336a(12) =112a(13) =48a(14) =24a(15) =30240a(16) =5040a(17) =1440a(18) =540a(19) =240a(20) =120a(21) =665280a(22) =95040a(23) =23760a(24) =7920a(25) =3168a(26) =1440a(27) =720a(28) =17297280a(29) =2162160