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

Terms

a(0) =1a(1) =-511a(2) =19684a(3) =-262655a(4) =1953126a(5) =-10058524a(6) =40353608a(7) =-134480383a(8) =387440173a(9) =-998047386a(10) =2357947692a(11) =-5170101020a(12) =10604499374a(13) =-20620693688a(14) =38445332184a(15) =-68853957119a(16) =118587876498a(17) =-197981928403a(18) =322687697780a(19) =-512998309530a(20) =794320419872