Triangle, read by rows, T(n, k) = binomial(n*binomial(n, k), k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =1a(6) =1a(7) =9a(8) =36a(9) =1a(10) =1a(11) =16a(12) =276a(13) =560a(14) =1a(15) =1a(16) =25a(17) =1225a(18) =19600a(19) =12650a(20) =1a(21) =1a(22) =36a(23) =4005a(24) =280840a(25) =2555190a(26) =376992a(27) =1a(28) =1a(29) =49