T(n,k) = S(2n,n-1,k-1), 0 <= k <= n, n >= 0, array S as in A050157.

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =4a(6) =5a(7) =9a(8) =14a(9) =15a(10) =14a(11) =28a(12) =48a(13) =55a(14) =56a(15) =42a(16) =90a(17) =165a(18) =200a(19) =209a(20) =210a(21) =132a(22) =297a(23) =572a(24) =726a(25) =780a(26) =791a(27) =792a(28) =429a(29) =1001