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

Terms

a(0) =1a(1) =-513a(2) =19684a(3) =-261633a(4) =1953126a(5) =-10097892a(6) =40353608a(7) =-133955073a(8) =387440173a(9) =-1001953638a(10) =2357947692a(11) =-5149983972a(12) =10604499374a(13) =-20701400904a(14) =38445332184a(15) =-68584996353a(16) =118587876498a(17) =-198756808749a(18) =322687697780a(19) =-511002214758