a(n) = Sum_{d|n} (-1)^(n/d+1)*d^9.

Terms

a(0) =1a(1) =511a(2) =19684a(3) =261631a(4) =1953126a(5) =10058524a(6) =40353608a(7) =133955071a(8) =387440173a(9) =998047386a(10) =2357947692a(11) =5149944604a(12) =10604499374a(13) =20620693688a(14) =38445332184a(15) =68584996351a(16) =118587876498a(17) =197981928403a(18) =322687697780a(19) =510998308506a(20) =794320419872