a(n) = n^2 - phi(n)*tau(n)^2.

Terms

a(0) =0a(1) =0a(2) =1a(3) =-2a(4) =9a(5) =4a(6) =25a(7) =0a(8) =27a(9) =36a(10) =81a(11) =0a(12) =121a(13) =100a(14) =97a(15) =56a(16) =225a(17) =108a(18) =289a(19) =112a(20) =249a(21) =324a(22) =441a(23) =64a(24) =445a(25) =484a(26) =441a(27) =352a(28) =729a(29) =388