a(n) = Sum_{d|n} d*2^(d-1) for n > 0.

Terms

a(0) =0a(1) =1a(2) =5a(3) =13a(4) =37a(5) =81a(6) =209a(7) =449a(8) =1061a(9) =2317a(10) =5205a(11) =11265a(12) =24817a(13) =53249a(14) =115141a(15) =245853a(16) =525349a(17) =1114113a(18) =2361809a(19) =4980737a(20) =10490997a(21) =22020557a(22) =46148613a(23) =96468993a(24) =201352433a(25) =419430481a(26) =872468485a(27) =1811941645a(28) =3758211557a(29) =7784628225