a(n) = n*2^(n-1) + 1.

Terms

a(0) =1a(1) =2a(2) =5a(3) =13a(4) =33a(5) =81a(6) =193a(7) =449a(8) =1025a(9) =2305a(10) =5121a(11) =11265a(12) =24577a(13) =53249a(14) =114689a(15) =245761a(16) =524289a(17) =1114113a(18) =2359297a(19) =4980737a(20) =10485761a(21) =22020097a(22) =46137345a(23) =96468993a(24) =201326593a(25) =419430401a(26) =872415233a(27) =1811939329a(28) =3758096385a(29) =7784628225