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

Terms

a(0) =1a(1) =-3a(2) =5a(3) =-8a(4) =14a(5) =-25a(6) =44a(7) =-77a(8) =135a(9) =-237a(10) =416a(11) =-730a(12) =1281a(13) =-2248a(14) =3945a(15) =-6923a(16) =12149a(17) =-21320a(18) =37414a(19) =-65657a(20) =115220a(21) =-202197a(22) =354831a(23) =-622685a(24) =1092736a(25) =-1917618a(26) =3365185a(27) =-5905488a(28) =10363409a(29) =-18186515