a(0) = 1; a(n) = sum_{k=1 to d(n)} [a(n-k)] where d(n) is number of positive divisors of n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =9a(6) =20a(7) =29a(8) =64a(9) =113a(10) =226a(11) =339a(12) =791a(13) =1130a(14) =2486a(15) =4746a(16) =9492a(17) =14238a(18) =32883a(19) =47121a(20) =110966a(21) =205208a(22) =396178a(23) =601386a(24) =1417472a(25) =2415036a(26) =4830072a(27) =9263966a(28) =18924110a(29) =28188076