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

Terms

a(0) =2a(1) =7a(2) =20a(3) =51a(4) =118a(5) =260a(6) =548a(7) =1121a(8) =2236a(9) =4373a(10) =8412a(11) =15960a(12) =29926a(13) =55547a(14) =102196a(15) =186567a(16) =338258a(17) =609532a(18) =1092328a(19) =1947829a(20) =3457724a(21) =6112873a(22) =10766328a(23) =18896880a(24) =33062090a(25) =57675631a(26) =100338836a(27) =174117915a(28) =301432558a(29) =520686644