a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 8.

Terms

a(0) =1a(1) =127a(2) =1093a(3) =8128a(4) =19531a(5) =138811a(6) =137257a(7) =520192a(8) =796797a(9) =2480437a(10) =1948717a(11) =8883904a(12) =5229043a(13) =17431639a(14) =21347383a(15) =33292288a(16) =25646167a(17) =101193219a(18) =49659541a(19) =158747968a(20) =150021901a(21) =247487059a(22) =154764793a(23) =568569856a(24) =305171875a(25) =664088461a(26) =580865013a(27) =1115624896