Sum_{d|n, d odd} d*2^(n/d).

Terms

a(0) =0a(1) =2a(2) =4a(3) =14a(4) =16a(5) =42a(6) =76a(7) =142a(8) =256a(9) =554a(10) =1044a(11) =2070a(12) =4144a(13) =8218a(14) =16412a(15) =32934a(16) =65536a(17) =131106a(18) =262372a(19) =524326a(20) =1048656a(21) =2097634a(22) =4194348a(23) =8388654a(24) =16777984a(25) =33554642a(26) =67108916a(27) =134219390a(28) =268435568a(29) =536870970