a(n) = T(n,0) + T(n,1) + ... + T(n,[ n/2 ]), T given by A027170.

Terms

a(0) =1a(1) =3a(2) =15a(3) =26a(4) =81a(5) =130a(6) =350a(7) =558a(8) =1417a(9) =2282a(10) =5632a(11) =9190a(12) =22296a(13) =36834a(14) =88280a(15) =147422a(16) =349929a(17) =589786a(18) =1388672a(19) =2359254a(20) =5516356a(21) =9437138a(22) =21931190a(23) =37748686a(24) =87250096a(25) =150994890a(26) =347306730a(27) =603979718a(28) =1383135310a(29) =2415919042