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

Terms

a(0) =1a(1) =0a(2) =50a(3) =250a(4) =3750a(5) =31250a(6) =343750a(7) =3281250a(8) =33593750a(9) =332031250a(10) =3339843750a(11) =33300781250a(12) =333496093750