a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 9.

Terms

a(0) =1a(1) =255a(2) =3280a(3) =32640a(4) =97656a(5) =836400a(6) =960800a(7) =4177920a(8) =7173360a(9) =24902280a(10) =21435888a(11) =107059200a(12) =67977560a(13) =245004000a(14) =320311680a(15) =534773760a(16) =435984840a(17) =1829206800a(18) =943531280a(19) =3187491840a(20) =3151424000a(21) =5466151440a(22) =3559590240a(23) =13703577600a(24) =7629375000a(25) =17334277800