a(1)=1, a(n)=ceiling(n/(n+1)*sum(k=1,n-1,a(k))).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =13a(6) =25a(7) =48a(8) =91a(9) =175a(10) =337a(11) =650a(12) =1258a(13) =2438a(14) =4735a(15) =9210a(16) =17940a(17) =34992a(18) =68331a(19) =133580a(20) =261391a(21) =511959a(22) =1003556a(23) =1968715a(24) =3864865a(25) =7592312a(26) =14923899a(27) =29352241a(28) =57761017a(29) =113723026