Expansion of x/((1+5x)(1-10x)).

Terms

a(0) =0a(1) =1a(2) =5a(3) =75a(4) =625a(5) =6875a(6) =65625a(7) =671875a(8) =6640625a(9) =66796875a(10) =666015625a(11) =6669921875a(12) =66650390625a(13) =666748046875