a(n) = Sum(p_j) * Sum(k_j) where n = Product(p_j^k_j).

Terms

a(0) =0a(1) =2a(2) =3a(3) =4a(4) =5a(5) =10a(6) =7a(7) =6a(8) =6a(9) =14a(10) =11a(11) =15a(12) =13a(13) =18a(14) =16a(15) =8a(16) =17a(17) =15a(18) =19a(19) =21a(20) =20a(21) =26a(22) =23a(23) =20a(24) =10a(25) =30a(26) =9a(27) =27a(28) =29a(29) =30