a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(n*j*k) / phi(n*k).

Terms

a(0) =1a(1) =6a(2) =16a(3) =37a(4) =62a(5) =121a(6) =154a(7) =256a(8) =339a(9) =499a(10) =560a(11) =884a(12) =910a(13) =1308a(14) =1516a(15) =1870a(16) =1979a(17) =2889a(18) =2756a(19) =3776a(20) =4023a(21) =4814a(22) =4795a(23) =6716a(24) =6330a(25) =7908a(26) =8301a(27) =9946a(28) =9520a(29) =13406