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

Terms

a(0) =0a(1) =1a(2) =10a(3) =54a(4) =224a(5) =800a(6) =2592a(7) =7840a(8) =22528a(9) =62208a(10) =166400a(11) =433664a(12) =1105920a(13) =2768896a(14) =6823936a(15) =16588800a(16) =39845888a(17) =94699520a(18) =222953472a(19) =520486912a(20) =1205862400a(21) =2774532096a(22) =6343884800a(23) =14422114304a(24) =32614907904a(25) =73400320000