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

Terms

a(0) =1a(1) =-1a(2) =2a(3) =-1a(4) =0a(5) =2a(6) =-3a(7) =3a(8) =-1a(9) =-2a(10) =5a(11) =-6a(12) =4a(13) =1a(14) =-7a(15) =11a(16) =-10a(17) =3a(18) =8a(19) =-18a(20) =21a(21) =-13a(22) =-5a(23) =26a(24) =-39a(25) =34a(26) =-8a(27) =-31a(28) =65a(29) =-73