Sum, over all binary strings w of length n, of the length of the shortest border of w.

Terms

a(0) =0a(1) =2a(2) =4a(3) =12a(4) =24a(5) =60a(6) =120a(7) =264a(8) =528a(9) =1116a(10) =2232a(11) =4584a(12) =9168a(13) =18616a(14) =37232a(15) =75056a(16) =150112a(17) =301556a(18) =603112a(19) =1209064a(20) =2418128a(21) =4842504a(22) =9685008a(23) =19383408a(24) =38766816a(25) =77562648a(26) =155125296a(27) =310312528a(28) =620625056a(29) =1241382832