Completely multiplicative with a(prime(k)) = prime(k+1).

Terms

a(0) =1a(1) =3a(2) =5a(3) =9a(4) =7a(5) =15a(6) =11a(7) =27a(8) =25a(9) =21a(10) =13a(11) =45a(12) =17a(13) =33a(14) =35a(15) =81a(16) =19a(17) =75a(18) =23a(19) =63a(20) =55a(21) =39a(22) =29a(23) =135a(24) =49a(25) =51a(26) =125a(27) =99a(28) =31a(29) =105