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

Terms

a(0) =1a(1) =4a(2) =16a(3) =36a(4) =100a(5) =144a(6) =324a(7) =484a(8) =784a(9) =1024a(10) =1764a(11) =2116a(12) =3364a(13) =4096a(14) =5184a(15) =6400a(16) =9216a(17) =10404a(18) =14400a(19) =16384a(20) =19600a(21) =22500a(22) =29584a(23) =32400a(24) =40000a(25) =44944a(26) =52900a(27) =58564a(28) =72900a(29) =77284