a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(2*j*k) / phi(k).

Terms

a(0) =1a(1) =9a(2) =21a(3) =55a(4) =93a(5) =163a(6) =241a(7) =383a(8) =507a(9) =709a(10) =915a(11) =1205a(12) =1497a(13) =1907a(14) =2220a(15) =2794a(16) =3306a(17) =3966a(18) =4610a(19) =5438a(20) =6075a(21) =7113a(22) =8067a(23) =9245a(24) =10272a(25) =11742a(26) =12900a(27) =14552a(28) =16086a(29) =17798