a(n) = Sum_{d|n} (-1)^(n/d+1)*d^8.

Terms

a(0) =1a(1) =255a(2) =6562a(3) =65279a(4) =390626a(5) =1673310a(6) =5764802a(7) =16711423a(8) =43053283a(9) =99609630a(10) =214358882a(11) =428360798a(12) =815730722a(13) =1470024510a(14) =2563287812a(15) =4278124287a(16) =6975757442a(17) =10978587165a(18) =16983563042a(19) =25499674654a(20) =37828630724a(21) =54661514910a(22) =78310985282a(23) =109660357726a(24) =152588281251a(25) =208011334110a(26) =282472589764