Number of permutation polynomials (mod n).

Terms

a(0) =1a(1) =2a(2) =6a(3) =8a(4) =120a(5) =12a(6) =5040a(7) =128a(8) =1296a(9) =240a(10) =39916800a(11) =48a(12) =6227020800a(13) =10080a(14) =720a(15) =8192a(17) =2592a(19) =960a(20) =30240a(21) =79833600a(23) =768a(24) =384000000a(25) =12454041600a(26) =25509168a(27) =40320a(29) =1440