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

Terms

a(0) =2a(1) =6a(2) =12a(3) =24a(4) =50a(5) =110a(6) =252a(7) =592a(8) =1410a(9) =3382a(10) =8140a(11) =19624a(12) =47346a(13) =114270a(14) =275836a(15) =665888a(16) =1607554a(17) =3880934a(18) =9369356a(19) =22619576a(20) =54608434a(21) =131836366a(22) =318281084a(23) =768398448a(24) =1855077890a(25) =4478554134a(26) =10812186060a(27) =26102926152a(28) =63018038258