a(n) = n*(n-3)*2^(n-2).

Terms

a(0) =0a(1) =-1a(2) =-2a(3) =0a(4) =16a(5) =80a(6) =288a(7) =896a(8) =2560a(9) =6912a(10) =17920a(11) =45056a(12) =110592a(13) =266240a(14) =630784a(15) =1474560a(16) =3407872a(17) =7798784a(18) =17694720a(19) =39845888a(20) =89128960a(21) =198180864a(22) =438304768a(23) =964689920a(24) =2113929216a(25) =4613734400a(26) =10032775168a(27) =21743271936a(28) =46976204800a(29) =101200166912