a(n) = (A102371(n) + n)/2.

Terms

a(0) =1a(1) =2a(2) =5a(3) =8a(4) =17a(5) =34a(6) =65a(7) =128a(8) =257a(9) =514a(10) =1029a(11) =2048a(12) =4097a(13) =8194a(14) =16385a(15) =32768a(16) =65537a(17) =131074a(18) =262149a(19) =524296a(20) =1048577a(21) =2097154a(22) =4194305a(23) =8388608a(24) =16777217a(25) =33554434a(26) =67108869a(27) =134217728a(28) =268435457a(29) =536870914