Product_{d|n, d>1} prime(A003415(d)), where A003415(x) gives the arithmetic derivative of x.

Terms

a(0) =1a(1) =2a(2) =2a(3) =14a(4) =2a(5) =44a(6) =2a(7) =518a(8) =26a(9) =68a(10) =2a(11) =16324a(12) =2a(13) =92a(14) =76a(15) =67858a(16) =2a(17) =41756a(18) =2a(19) =42364a(20) =116a(21) =164a(22) =2a(23) =116569684a(24) =58a(25) =188a(26) =2678a(27) =84364a(28) =2a(29) =3609848