Positive solution to 2^(n-1) = (1/n) * Sum_{d|n} a(d) * a(n/d).

Terms

a(0) =1a(1) =2a(2) =6a(3) =14a(4) =40a(5) =84a(6) =224a(7) =484a(8) =1134a(9) =2480a(10) =5632a(11) =12036a(12) =26624a(13) =56896a(14) =122640a(15) =261078a(16) =557056a(17) =1176876a(18) =2490368a(19) =5237360a(20) =11008704a(21) =23057408a(22) =48234496a(23) =100635144a(24) =209714400a(25) =436154368a(26) =905962860a(27) =1878931264a(28) =3892314112a(29) =8052800160