a(n) = 1 + Sum_{ k < n and k | n} a(k).

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =6a(5) =9a(6) =10a(7) =14a(8) =16a(9) =19a(10) =20a(11) =28a(12) =29a(13) =32a(14) =35a(15) =43a(16) =44a(17) =52a(18) =53a(19) =61a(20) =64a(21) =67a(22) =68a(23) =88a(24) =90a(25) =93a(26) =97a(27) =105a(28) =106a(29) =119