a(n) = n*(n+1)*2^(n-2).

Terms

a(0) =0a(1) =1a(2) =6a(3) =24a(4) =80a(5) =240a(6) =672a(7) =1792a(8) =4608a(9) =11520a(10) =28160a(11) =67584a(12) =159744a(13) =372736a(14) =860160a(15) =1966080a(16) =4456448a(17) =10027008a(18) =22413312a(19) =49807360a(20) =110100480a(21) =242221056a(22) =530579456a(23) =1157627904a(24) =2516582400a(25) =5452595200a(26) =11777605632a(27) =25367150592a(28) =54492397568a(29) =116769423360