a(n) = n*phi(n).

Terms

a(0) =1a(1) =2a(2) =6a(3) =8a(4) =20a(5) =12a(6) =42a(7) =32a(8) =54a(9) =40a(10) =110a(11) =48a(12) =156a(13) =84a(14) =120a(15) =128a(16) =272a(17) =108a(18) =342a(19) =160a(20) =252a(21) =220a(22) =506a(23) =192a(24) =500a(25) =312a(26) =486a(27) =336a(28) =812a(29) =240