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

Terms

a(0) =2a(1) =10a(2) =18a(3) =38a(4) =72a(5) =136a(6) =250a(7) =454a(8) =814a(9) =1446a(10) =2548a(11) =4460a(12) =7762a(13) =13442a(14) =23178a(15) =39814a(16) =68160a(17) =116336a(18) =198026a(19) =336254a(20) =569702a(21) =963270a(22) =1625708a(23) =2739028a(24) =4607522a(25) =7739386a(26) =12982530a(27) =21750374a(28) =36396984a(29) =60839896