Triangle read by rows: T(n,m) = 1 + ((-1 + binomial(n, m))*(n!)^2)/(m!*(n - m)!).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =5a(5) =1a(6) =1a(7) =37a(8) =37a(9) =1a(10) =1a(11) =289a(12) =721a(13) =289a(14) =1a(15) =1a(16) =2401a(17) =10801a(18) =10801a(19) =2401a(20) =1a(21) =1a(22) =21601a(23) =151201a(24) =273601a(25) =151201a(26) =21601a(27) =1a(28) =1a(29) =211681