a(1) = 1; a(n) = Sum_{d|n, d<n} prime(n/d) * a(d).

Terms

a(0) =1a(1) =3a(2) =5a(3) =16a(4) =11a(5) =43a(6) =17a(7) =88a(8) =48a(9) =95a(10) =31a(11) =320a(12) =41a(13) =145a(14) =157a(15) =486a(16) =59a(17) =554a(18) =67a(19) =696a(20) =243a(21) =265a(22) =83a(23) =2204a(24) =218a(25) =347a(26) =458a(27) =1062a(28) =109a(29) =1961