Specialization of the Elementary Symmetric Functions e(n) at x_i -> Euler phi(i).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =1a(7) =4a(8) =5a(9) =2a(10) =1a(11) =6a(12) =13a(13) =12a(14) =4a(15) =1a(16) =10a(17) =37a(18) =64a(19) =52a(20) =16a(21) =1a(22) =12a(23) =57a(24) =138a(25) =180a(26) =120a(27) =32a(28) =1a(29) =18