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

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =4a(5) =60a(6) =6a(7) =168a(8) =48a(9) =360a(10) =10a(11) =47520a(12) =12a(13) =1092a(14) =1680a(15) =20160a(16) =16a(17) =440640a(18) =18a(19) =820800a(20) =5040a(21) =4620a(22) =22a(23) =734469120a(24) =480a(25) =7800a(26) =11232a(27) =4953312a(28) =28a(29) =3946320000