Triangle, read by rows, T(n, k) = binomial(n*binomial(n, floor((n-k)/2)), k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =1a(7) =9a(8) =3a(9) =1a(10) =1a(11) =16a(12) =120a(13) =4a(14) =1a(15) =1a(16) =50a(17) =300a(18) =2300a(19) =5a(20) =1a(21) =1a(22) =90a(23) =4005a(24) =7140a(25) =58905a(26) =6a(27) =1a(28) =1a(29) =245