Expansion of (1+5x-40x^2)/((1-5x)(1+5x)).

Terms

a(0) =1a(1) =5a(2) =-15a(3) =125a(4) =-375a(5) =3125a(6) =-9375a(7) =78125a(8) =-234375a(9) =1953125a(10) =-5859375a(11) =48828125a(12) =-146484375a(13) =1220703125a(14) =-3662109375a(15) =30517578125a(16) =-91552734375a(17) =762939453125