Expansion of (1-x)/(1+2*x+x^3).

Terms

a(0) =1a(1) =-3a(2) =6a(3) =-13a(4) =29a(5) =-64a(6) =141a(7) =-311a(8) =686a(9) =-1513a(10) =3337a(11) =-7360a(12) =16233a(13) =-35803a(14) =78966a(15) =-174165a(16) =384133a(17) =-847232a(18) =1868629a(19) =-4121391a(20) =9090014a(21) =-20048657a(22) =44218705a(23) =-97527424a(24) =215103505a(25) =-474425715a(26) =1046378854a(27) =-2307861213a(28) =5090148141a(29) =-11226675136