Expansion of (1-6*x)/(1-10*x).

Terms

a(0) =1a(1) =4a(2) =40a(3) =400a(4) =4000a(5) =40000a(6) =400000a(7) =4000000a(8) =40000000a(9) =400000000a(10) =4000000000a(11) =40000000000a(12) =400000000000