a(n) = Sum{T(n,i): i=0,1,...,n}, where T is given by A048113.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =2a(5) =4a(6) =8a(7) =12a(8) =24a(9) =48a(10) =84a(11) =168a(12) =336a(13) =624a(14) =1248a(15) =2496a(16) =4776a(17) =9552a(18) =19104a(19) =37152a(20) =74304a(21) =148608a(22) =291768a(23) =583536a(24) =1167072a(25) =2304912a(26) =4609824a(27) =9219648a(28) =18277776a(29) =36555552