Inverse Euler transform of the Euler totient function phi = A000010.

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =0a(5) =2a(6) =-3a(7) =4a(8) =-4a(9) =4a(10) =-9a(11) =14a(12) =-19a(13) =30a(14) =-42a(15) =50a(16) =-76a(17) =128a(18) =-194a(19) =286a(20) =-412a(21) =598a(22) =-909a(23) =1386a(24) =-2100a(25) =3178a(26) =-4763a(27) =7122a(28) =-10758a(29) =16414