Jordan function J_2(n) (a generalization of phi(n)).

Terms

a(0) =1a(1) =3a(2) =8a(3) =12a(4) =24a(5) =24a(6) =48a(7) =48a(8) =72a(9) =72a(10) =120a(11) =96a(12) =168a(13) =144a(14) =192a(15) =192a(16) =288a(17) =216a(18) =360a(19) =288a(20) =384a(21) =360a(22) =528a(23) =384a(24) =600a(25) =504a(26) =648a(27) =576a(28) =840a(29) =576