a(1) = 1; a(n) = Sum_{k=1..n-1} a(floor((n-1)/k)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =11a(6) =17a(7) =24a(8) =34a(9) =46a(10) =62a(11) =79a(12) =104a(13) =130a(14) =163a(15) =201a(16) =249a(17) =298a(18) =363a(19) =429a(20) =513a(21) =605a(22) =714a(23) =824a(24) =966a(25) =1112a(26) =1284a(27) =1468a(28) =1687a(29) =1907