a(n) = binomial((n-1)^2, n).A178842a(n) = binomial((n-1)^2, n).Terms a(0) =0a(1) =0a(2) =4a(3) =126a(4) =4368a(5) =177100a(6) =8347680a(7) =450978066a(8) =27540584512External referencesoeis: A178842