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

Terms

a(0) =2a(1) =3a(2) =6a(3) =7a(4) =22a(5) =8a(6) =74a(7) =29a(8) =90a(9) =30a(10) =1207a(11) =31a(12) =4118a(13) =121a(14) =466a(15) =467a(16) =67266a(17) =122a(18) =236984a(19) =496a(20) =7452a(21) =1973a(22) =3956273a(23) =497a(24) =1305399a(25) =8014a(26) =405387a(27) =8015a(28) =222108532a(29) =498