Number triangle T(n,k) = 2^(n-k)*C(2*n,n-k).

Terms

a(0) =1a(1) =4a(2) =1a(3) =24a(4) =8a(5) =1a(6) =160a(7) =60a(8) =12a(9) =1a(10) =1120a(11) =448a(12) =112a(13) =16a(14) =1a(15) =8064a(16) =3360a(17) =960a(18) =180a(19) =20a(20) =1a(21) =59136a(22) =25344a(23) =7920a(24) =1760a(25) =264a(26) =24a(27) =1a(28) =439296a(29) =192192