a(n) = lcm(n, phi(n)).

Terms

a(0) =1a(1) =2a(2) =6a(3) =4a(4) =20a(5) =6a(6) =42a(7) =8a(8) =18a(9) =20a(10) =110a(11) =12a(12) =156a(13) =42a(14) =120a(15) =16a(16) =272a(17) =18a(18) =342a(19) =40a(20) =84a(21) =110a(22) =506a(23) =24a(24) =100a(25) =156a(26) =54a(27) =84a(28) =812a(29) =120