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

Terms

a(0) =1a(1) =-257a(2) =6562a(3) =-65281a(4) =390626a(5) =-1686434a(6) =5764802a(7) =-16711425a(8) =43053283a(9) =-100390882a(10) =214358882a(11) =-428373922a(12) =815730722a(13) =-1481554114a(14) =2563287812a(15) =-4278124289a(16) =6975757442a(17) =-11064693731a(18) =16983563042a(19) =-25500455906a(20) =37828630724a(21) =-55090232674