Expansion of (1-x-x^2)^2*(1+x-x^2)^2/((1-3*x+x^2)*(1-x)^2*(1+x)^4).

Terms

a(0) =1a(1) =1a(2) =1a(3) =6a(4) =12a(5) =36a(6) =91a(7) =241a(8) =632a(9) =1651a(10) =4333a(11) =11328a(12) =29684a(13) =77678a(14) =203415a(15) =532483a(16) =1394144a(17) =3649813a(18) =9555465a(19) =25016378a(20) =65493916a(21) =171465080a(22) =448901667a(23) =1175239525a(24) =3076817368a(25) =8055212055a(26) =21088819397a(27) =55211245460a(28) =144544917748