a(n) = 1/(Sum_{k=1..n} 1/phi(A341810(n)*k)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =8a(6) =3a(7) =24a(8) =12a(9) =3a(10) =120a(11) =30a(12) =9a(13) =45a(14) =32a(15) =120a(16) =320a(17) =160a(18) =720a(19) =2880a(20) =256a(21) =1280a(22) =15840a(23) =1408a(24) =704a(25) =2112a(26) =3168a(27) =9504a(28) =88704a(29) =199584