a(n) = Product_{k=0..2*n-1} (3*n+k-1).A384301a(n) = Product_{k=0..2*n-1} (3*n+k-1).Terms a(0) =1a(1) =6a(2) =1680a(3) =1235520a(4) =1764322560External referencesoeis: A384301