a(n) = 2^(n-6)*n*(n^3 - 6*n^2 + 19*n - 14).

Terms

a(0) =0a(1) =0a(2) =1a(3) =6a(4) =30a(5) =140a(6) =600a(7) =2352a(8) =8512a(9) =28800a(10) =92160a(11) =281600a(12) =827904a(13) =2356224a(14) =6522880a(15) =17633280a(16) =46694400a(17) =121438208a(18) =310837248a(19) =784465920a(20) =1954938880a(21) =4816896000a(22) =11747721216a(23) =28386000896a(24) =68010639360a(25) =161690419200a(26) =381681664000a(27) =895098028032