Table: T(n,k) = n!*binomial(n+1,2*k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =6a(6) =36a(7) =6a(8) =24a(9) =240a(10) =120a(11) =120a(12) =1800a(13) =1800a(14) =120a(15) =720a(16) =15120a(17) =25200a(18) =5040a(19) =5040a(20) =141120a(21) =352800a(22) =141120a(23) =5040a(24) =40320a(25) =1451520a(26) =5080320a(27) =3386880a(28) =362880a(29) =362880