Product of all n - d, where 1 < d < n and d is a divisor of n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =1a(5) =12a(6) =1a(7) =24a(8) =6a(9) =40a(10) =1a(11) =4320a(12) =1a(13) =84a(14) =120a(15) =1344a(16) =1a(17) =25920a(18) =1a(19) =43200a(20) =252a(21) =220a(22) =1a(23) =31933440a(24) =20a(25) =312a(26) =432a(27) =183456a(28) =1a(29) =136080000