Sequence generated from A089080.

Terms

a(0) =1a(1) =2a(2) =6a(3) =12a(4) =48a(5) =96a(6) =288a(7) =576a(8) =2880a(9) =5760a(10) =17280a(11) =34560a(12) =138240a(13) =276480a(14) =829440a(15) =1658880a(16) =9953280a(17) =19906560a(18) =59719680a(19) =119439360a(20) =477757440a(21) =955514880a(22) =2866544640a(23) =5733089280a(24) =28665446400a(25) =57330892800a(26) =171992678400a(27) =343985356800