Sum of eighth powers of unitary divisors.

Terms

a(0) =1a(1) =257a(2) =6562a(3) =65537a(4) =390626a(5) =1686434a(6) =5764802a(7) =16777217a(8) =43046722a(9) =100390882a(10) =214358882a(11) =430053794a(12) =815730722a(13) =1481554114a(14) =2563287812a(15) =4294967297a(16) =6975757442a(17) =11063007554a(18) =16983563042a(19) =25600456162a(20) =37828630724