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

Terms

a(0) =0a(1) =2a(2) =6a(3) =16a(4) =36a(5) =82a(6) =176a(7) =372a(8) =768a(9) =1582a(10) =3224a(11) =6534a(12) =13166a(13) =26504a(14) =53244a(15) =106824a(16) =214060a(17) =428764a(18) =858400a(19) =1718056a(20) =3437734a(21) =6877896a(22) =13759154a(23) =27523128a(24) =55052582a(25) =110114618a(26) =220242288a(27) =440503282a(28) =881031714a(29) =1762100362