a(n) = Sum_{d|n, n/d odd} d^8 for n > 0.

Terms

a(0) =1a(1) =256a(2) =6562a(3) =65536a(4) =390626a(5) =1679872a(6) =5764802a(7) =16777216a(8) =43053283a(9) =100000256a(10) =214358882a(11) =430047232a(12) =815730722a(13) =1475789312a(14) =2563287812a(15) =4294967296a(16) =6975757442a(17) =11021640448a(18) =16983563042a(19) =25600065536a(20) =37828630724a(21) =54875873792a(22) =78310985282