a(n) = 2^phi(n) - Sum_{j=0..n} binomial(phi(n), phi(j)).

Terms

a(0) =0a(1) =-1a(2) =-2a(3) =-3a(4) =-6a(5) =-4a(6) =-10a(7) =-13a(8) =-26a(9) =-14a(10) =-183a(11) =-15a(12) =-22a(13) =-57a(14) =-210a(15) =-211a(16) =-1730a(17) =-58a(18) =25160a(19) =-240a(20) =-3356a(21) =-949a(22) =238031a(23) =-241a(24) =-256823a(25) =-3918a(26) =-143243a(27) =-3919a(28) =46326924a(29) =-242